* [PATCH v3 0/4] Simplify internal single-threaded usage
@ 2022-06-21 20:32 Adhemerval Zanella
2022-06-21 20:32 ` [PATCH v3 1/4] misc: Optimize internal usage of __libc_single_threaded Adhemerval Zanella
` (3 more replies)
0 siblings, 4 replies; 12+ messages in thread
From: Adhemerval Zanella @ 2022-06-21 20:32 UTC (permalink / raw)
To: libc-alpha, Wilco Dijkstra, Fangrui Song
The glibc currently has three different internal ways to check if a
process is single-threaded: the exported global variable
__libc_single_threaded, the internal-only __libc_multiple_threads, and
the variant used by some architectures and allocated on TCB,
multiple_threads. Also each port can define SINGLE_THREAD_BY_GLOBAL
to either use __libc_multiple_threads or multiple_threads.
The __libc_single_threaded and __libc_multiple_threads have essentially
the same semantic: both are global variables where the value is not
reset if/when the process becomes multi-threaded. The issue of using
__libc_single_threaded internally is since it is accessed through copy
relocation, both values must be updated. This is fixed in the first
patch.
The second patch replaces __libc_multiple_threads with
__libc_single_threaded, while also fixing a bug where architectures that
define SINGLE_THREAD_BY_GLOBAL does not enable the optimization.
The third patch replaces multiple_threads with __libc_single_threaded,
to simplify a possible single-thread lock optimization. On most
architectures, accessing an internal global variable should be as fast
as through the TCB (it seems that only legacy ABIs that require extra
code sequence to materialize global access, such as i686 and sparc,
using the TCB would be faster, however it is mitigated when the
SINGLE_THREAD_P is accessed in large code blocks).
The x86 is only architecture that optimizes the lock access directly by
reimplementing atomic operations. In this case, the affected
implementations are rewritten to use SINGLE_THREAD_P macro, while some
unused macros are just removed (for instance atomic_add_zero). The idea
is to just phase out this specific atomic implementation in favor of
compiler builtins and move the single-thread optimization to be
arch-neutral.
In the last patch just remove the single-thread.h header and move the
definition to internal sys/single_threaded.h, so now there is only
one place to add such optimization.
v3:
* Replace __libc_dlsym with a new macro to define both internal and
external symbol (STV_HIDDEN and STV_DEFAULT), so pthread_create
can update both.
* Add more SINGLE_THREAD_P usage now that it is based on
__libc_single_threaded on all architectures.
* Fixed i686 compare and swap macro refactor.
v2:
* Add RTLD_DEFAULT support for __libc_dlsym and use it instead of
___dlsym.
* Simplify the x86 atomic macros.
Adhemerval Zanella (4):
misc: Optimize internal usage of __libc_single_threaded
Replace __libc_multiple_threads with __libc_single_threaded
Remove usage of TLS_MULTIPLE_THREADS_IN_TCB
Remove single-thread.h
elf/libc_early_init.c | 2 +-
include/libc-symbols.h | 22 +
include/sys/single_threaded.h | 20 +-
misc/single_threaded.c | 2 +
misc/tst-atomic.c | 1 +
nptl/Makefile | 1 -
nptl/allocatestack.c | 12 -
nptl/descr.h | 17 +-
nptl/libc_multiple_threads.c | 28 --
nptl/pthread_cancel.c | 9 +-
nptl/pthread_create.c | 10 +-
posix/fork.c | 2 +-
sysdeps/generic/single-thread.h | 25 -
sysdeps/i386/htl/tcb-offsets.sym | 1 -
sysdeps/i386/nptl/tcb-offsets.sym | 1 -
sysdeps/i386/nptl/tls.h | 4 +-
sysdeps/ia64/nptl/tcb-offsets.sym | 1 -
sysdeps/ia64/nptl/tls.h | 2 -
sysdeps/mach/hurd/i386/tls.h | 4 +-
sysdeps/mach/hurd/sysdep-cancel.h | 5 -
sysdeps/nios2/nptl/tcb-offsets.sym | 1 -
sysdeps/nptl/setxid.h | 2 +-
sysdeps/or1k/nptl/tls.h | 2 -
sysdeps/powerpc/nptl/tcb-offsets.sym | 3 -
sysdeps/powerpc/nptl/tls.h | 3 -
sysdeps/s390/nptl/tcb-offsets.sym | 1 -
sysdeps/s390/nptl/tls.h | 6 +-
sysdeps/sh/nptl/tcb-offsets.sym | 1 -
sysdeps/sh/nptl/tls.h | 2 -
sysdeps/sparc/nptl/tcb-offsets.sym | 1 -
sysdeps/sparc/nptl/tls.h | 2 +-
sysdeps/unix/sysdep.h | 2 +-
sysdeps/unix/sysv/linux/aarch64/sysdep.h | 2 -
sysdeps/unix/sysv/linux/alpha/sysdep.h | 2 -
sysdeps/unix/sysv/linux/arc/sysdep.h | 2 -
sysdeps/unix/sysv/linux/arm/sysdep.h | 2 -
sysdeps/unix/sysv/linux/hppa/sysdep.h | 2 -
sysdeps/unix/sysv/linux/microblaze/sysdep.h | 2 -
sysdeps/unix/sysv/linux/s390/sysdep.h | 3 -
sysdeps/unix/sysv/linux/single-thread.h | 44 --
sysdeps/unix/sysv/linux/x86_64/sysdep.h | 2 -
sysdeps/x86/atomic-machine.h | 488 ++++++--------------
sysdeps/x86_64/nptl/tcb-offsets.sym | 1 -
sysdeps/x86_64/nptl/tls.h | 2 +-
44 files changed, 199 insertions(+), 548 deletions(-)
delete mode 100644 nptl/libc_multiple_threads.c
delete mode 100644 sysdeps/generic/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/single-thread.h
--
2.34.1
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v3 1/4] misc: Optimize internal usage of __libc_single_threaded
2022-06-21 20:32 [PATCH v3 0/4] Simplify internal single-threaded usage Adhemerval Zanella
@ 2022-06-21 20:32 ` Adhemerval Zanella
2022-06-23 4:15 ` Fangrui Song
2022-06-21 20:32 ` [PATCH v3 2/4] Replace __libc_multiple_threads with __libc_single_threaded Adhemerval Zanella
` (2 subsequent siblings)
3 siblings, 1 reply; 12+ messages in thread
From: Adhemerval Zanella @ 2022-06-21 20:32 UTC (permalink / raw)
To: libc-alpha, Wilco Dijkstra, Fangrui Song
By adding an internal alias to avoid the GOT indirection.
On some architecture, __libc_single_thread may be accessed through
copy relocations and thus it requires to update also the copies
default copy.
This is done by adding a new internal macro,
libc_hidden_data_{proto,def}, which has an addition argument that
specifies the alias name (instead of default __GI_ one).
Checked on x86_64-linux-gnu and i686-linux-gnu.
---
elf/libc_early_init.c | 2 +-
include/libc-symbols.h | 22 ++++++++++++++++++++++
include/sys/single_threaded.h | 11 +++++++++++
misc/single_threaded.c | 2 ++
nptl/pthread_create.c | 5 ++++-
posix/fork.c | 2 +-
sysdeps/nptl/setxid.h | 2 +-
7 files changed, 42 insertions(+), 4 deletions(-)
diff --git a/elf/libc_early_init.c b/elf/libc_early_init.c
index 3c4a19cf6b..affc46fefc 100644
--- a/elf/libc_early_init.c
+++ b/elf/libc_early_init.c
@@ -38,7 +38,7 @@ __libc_early_init (_Bool initial)
__libc_single_threaded = initial;
#ifdef SHARED
- __libc_initial = initial;
+ __libc_single_threaded_internal = __libc_initial = initial;
#endif
__pthread_early_init ();
diff --git a/include/libc-symbols.h b/include/libc-symbols.h
index 4bb3d8c7ba..4fde839471 100644
--- a/include/libc-symbols.h
+++ b/include/libc-symbols.h
@@ -534,11 +534,15 @@ for linking")
__attribute__ ((visibility ("hidden"), ##attrs))
# define hidden_proto(name, attrs...) \
__hidden_proto (name, , __GI_##name, ##attrs)
+# define hidden_proto_alias(name, alias, attrs...) \
+ __hidden_proto_alias (name, , alias, ##attrs)
# define hidden_tls_proto(name, attrs...) \
__hidden_proto (name, __thread, __GI_##name, ##attrs)
# define __hidden_proto(name, thread, internal, attrs...) \
extern thread __typeof (name) name __asm__ (__hidden_asmname (#internal)) \
__hidden_proto_hiddenattr (attrs);
+# define __hidden_proto_alias(name, thread, internal, attrs...) \
+ extern thread __typeof (name) internal __hidden_proto_hiddenattr (attrs);
# define __hidden_asmname(name) \
__hidden_asmname1 (__USER_LABEL_PREFIX__, name)
# define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name)
@@ -554,7 +558,10 @@ for linking")
# define hidden_ver(local, name) __hidden_ver1(local, __GI_##name, name);
# define hidden_data_ver(local, name) hidden_ver(local, name)
# define hidden_def(name) __hidden_ver1(__GI_##name, name, name);
+# define hidden_def_alias(name, internal) \
+ strong_alias (name, internal)
# define hidden_data_def(name) hidden_def(name)
+# define hidden_data_def_alias(name, alias) hidden_def_alias(name, alias)
# define hidden_tls_def(name) \
__hidden_ver2 (__thread, __GI_##name, name, name);
# define hidden_weak(name) \
@@ -581,9 +588,11 @@ for linking")
hidden_proto doesn't make sense for assembly but the equivalent
is to call via the HIDDEN_JUMPTARGET macro instead of JUMPTARGET. */
# define hidden_def(name) strong_alias (name, __GI_##name)
+# define hidden_def_alias(name, alias) strong_alias (name, alias)
# define hidden_weak(name) hidden_def (name)
# define hidden_ver(local, name) strong_alias (local, __GI_##name)
# define hidden_data_def(name) strong_data_alias (name, __GI_##name)
+# define hidden_data_def_alias(name, alias) strong_data_alias (name, alias)
# define hidden_tls_def(name) hidden_data_def (name)
# define hidden_data_weak(name) hidden_data_def (name)
# define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name)
@@ -598,12 +607,17 @@ for linking")
__attribute__ ((visibility ("hidden"), ##attrs))
# define hidden_proto(name, attrs...) \
__hidden_proto (name, , name, ##attrs)
+# define hidden_proto_alias(name, alias, attrs...) \
+ __hidden_proto_alias (name, , alias, ##attrs)
# define hidden_tls_proto(name, attrs...) \
__hidden_proto (name, __thread, name, ##attrs)
# define __hidden_proto(name, thread, internal, attrs...) \
extern thread __typeof (name) name __hidden_proto_hiddenattr (attrs);
+# define __hidden_proto_alias(name, thread, internal, attrs...) \
+ extern thread __typeof (name) internal __hidden_proto_hiddenattr (attrs);
# else
# define hidden_proto(name, attrs...)
+# define hidden_proto_alias(name, alias, attrs...)
# define hidden_tls_proto(name, attrs...)
# endif
# else
@@ -611,9 +625,11 @@ for linking")
# endif /* Not __ASSEMBLER__ */
# define hidden_weak(name)
# define hidden_def(name)
+# define hidden_def_alias(name, alias)
# define hidden_ver(local, name)
# define hidden_data_weak(name)
# define hidden_data_def(name)
+# define hidden_data_def_alias(name, alias)
# define hidden_tls_def(name)
# define hidden_data_ver(local, name)
# define hidden_nolink(name, lib, version)
@@ -621,22 +637,28 @@ for linking")
#if IS_IN (libc)
# define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
+# define libc_hidden_proto_alias(name, alias, attrs...) \
+ hidden_proto_alias (name, alias, ##attrs)
# define libc_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
# define libc_hidden_def(name) hidden_def (name)
+# define libc_hidden_def_alias(name, alias) hidden_def_alias (name, alias)
# define libc_hidden_weak(name) hidden_weak (name)
# define libc_hidden_nolink_sunrpc(name, version) hidden_nolink (name, libc, version)
# define libc_hidden_ver(local, name) hidden_ver (local, name)
# define libc_hidden_data_def(name) hidden_data_def (name)
+# define libc_hidden_data_def_alias(name, alias) hidden_data_def_alias (name, alias)
# define libc_hidden_tls_def(name) hidden_tls_def (name)
# define libc_hidden_data_weak(name) hidden_data_weak (name)
# define libc_hidden_data_ver(local, name) hidden_data_ver (local, name)
#else
# define libc_hidden_proto(name, attrs...)
+# define libc_hidden_proto_alias(name, alias, attrs...)
# define libc_hidden_tls_proto(name, attrs...)
# define libc_hidden_def(name)
# define libc_hidden_weak(name)
# define libc_hidden_ver(local, name)
# define libc_hidden_data_def(name)
+# define libc_hidden_data_def_alias(name, alias)
# define libc_hidden_tls_def(name)
# define libc_hidden_data_weak(name)
# define libc_hidden_data_ver(local, name)
diff --git a/include/sys/single_threaded.h b/include/sys/single_threaded.h
index 18f6972482..2015742be0 100644
--- a/include/sys/single_threaded.h
+++ b/include/sys/single_threaded.h
@@ -1 +1,12 @@
#include <misc/sys/single_threaded.h>
+
+#ifndef _ISOMAC
+
+libc_hidden_proto_alias (__libc_single_threaded,
+ __libc_single_threaded_internal);
+
+#if !defined SHARED || !IS_IN(libc)
+# define __libc_single_threaded_internal __libc_single_threaded
+#endif
+
+#endif
diff --git a/misc/single_threaded.c b/misc/single_threaded.c
index 96ada9137b..9b0746a69c 100644
--- a/misc/single_threaded.c
+++ b/misc/single_threaded.c
@@ -25,3 +25,5 @@ char __libc_single_threaded;
#else
char __libc_single_threaded = 1;
#endif
+libc_hidden_data_def_alias (__libc_single_threaded,
+ __libc_single_threaded_internal)
diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index e7a099acb7..5b98e053d6 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -624,9 +624,12 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
/* Avoid a data race in the multi-threaded case, and call the
deferred initialization only once. */
- if (__libc_single_threaded)
+ if (__libc_single_threaded_internal)
{
late_init ();
+ __libc_single_threaded_internal = 0;
+ /* __libc_single_threaded can be accessed through copy relocations, so
+ it requires to update the external copy. */
__libc_single_threaded = 0;
}
diff --git a/posix/fork.c b/posix/fork.c
index e1be3422ea..987916a175 100644
--- a/posix/fork.c
+++ b/posix/fork.c
@@ -45,7 +45,7 @@ __libc_fork (void)
requirement for fork (Austin Group tracker issue #62) this is
best effort to make is async-signal-safe at least for single-thread
case. */
- bool multiple_threads = __libc_single_threaded == 0;
+ bool multiple_threads = __libc_single_threaded_internal == 0;
uint64_t lastrun;
lastrun = __run_prefork_handlers (multiple_threads);
diff --git a/sysdeps/nptl/setxid.h b/sysdeps/nptl/setxid.h
index b821d6bc07..b87cad7b18 100644
--- a/sysdeps/nptl/setxid.h
+++ b/sysdeps/nptl/setxid.h
@@ -29,7 +29,7 @@
#define INLINE_SETXID_SYSCALL(name, nr, args...) \
({ \
int __result; \
- if (!__libc_single_threaded) \
+ if (!__libc_single_threaded_internal) \
{ \
struct xid_command __cmd; \
__cmd.syscall_no = __NR_##name; \
--
2.34.1
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v3 2/4] Replace __libc_multiple_threads with __libc_single_threaded
2022-06-21 20:32 [PATCH v3 0/4] Simplify internal single-threaded usage Adhemerval Zanella
2022-06-21 20:32 ` [PATCH v3 1/4] misc: Optimize internal usage of __libc_single_threaded Adhemerval Zanella
@ 2022-06-21 20:32 ` Adhemerval Zanella
2022-06-22 11:04 ` Yann Droneaud
2022-07-05 11:34 ` Wilco Dijkstra
2022-06-21 20:32 ` [PATCH v3 3/4] Remove usage of TLS_MULTIPLE_THREADS_IN_TCB Adhemerval Zanella
2022-06-21 20:32 ` [PATCH v3 4/4] Remove single-thread.h Adhemerval Zanella
3 siblings, 2 replies; 12+ messages in thread
From: Adhemerval Zanella @ 2022-06-21 20:32 UTC (permalink / raw)
To: libc-alpha, Wilco Dijkstra, Fangrui Song
And also fixes the SINGLE_THREAD_P macro for SINGLE_THREAD_BY_GLOBAL,
since header inclusion single-thread.h is in the wrong order, the define
needs to come before including sysdeps/unix/sysdep.h. The macro
is now moved to a per-arch single-threade.h header.
The SINGLE_THREAD_P is used on some more places.
Checked on aarch64-linux-gnu and x86_64-linux-gnu.
---
nptl/Makefile | 1 -
nptl/allocatestack.c | 6 ----
nptl/libc_multiple_threads.c | 28 -------------------
nptl/pthread_cancel.c | 2 +-
posix/fork.c | 2 +-
sysdeps/nptl/setxid.h | 2 +-
.../unix/sysv/linux/aarch64/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/aarch64/sysdep.h | 2 --
sysdeps/unix/sysv/linux/alpha/sysdep.h | 2 --
sysdeps/unix/sysv/linux/arc/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/arc/sysdep.h | 2 --
sysdeps/unix/sysv/linux/arm/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/arm/sysdep.h | 2 --
sysdeps/unix/sysv/linux/hppa/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/hppa/sysdep.h | 2 --
.../sysv/linux/microblaze/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/microblaze/sysdep.h | 2 --
sysdeps/unix/sysv/linux/s390/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/s390/sysdep.h | 3 --
sysdeps/unix/sysv/linux/single-thread.h | 11 ++++----
.../unix/sysv/linux/x86_64/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/x86_64/sysdep.h | 2 --
22 files changed, 22 insertions(+), 61 deletions(-)
delete mode 100644 nptl/libc_multiple_threads.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/single-thread.h
create mode 100644 sysdeps/unix/sysv/linux/arc/single-thread.h
create mode 100644 sysdeps/unix/sysv/linux/arm/single-thread.h
create mode 100644 sysdeps/unix/sysv/linux/hppa/single-thread.h
create mode 100644 sysdeps/unix/sysv/linux/microblaze/single-thread.h
create mode 100644 sysdeps/unix/sysv/linux/s390/single-thread.h
create mode 100644 sysdeps/unix/sysv/linux/x86_64/single-thread.h
diff --git a/nptl/Makefile b/nptl/Makefile
index b585663974..3d2ce8af8a 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -50,7 +50,6 @@ routines = \
events \
futex-internal \
libc-cleanup \
- libc_multiple_threads \
lowlevellock \
nptl-stack \
nptl_deallocate_tsd \
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c
index 01a282f3f6..98f5f6dd85 100644
--- a/nptl/allocatestack.c
+++ b/nptl/allocatestack.c
@@ -292,9 +292,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
/* This is at least the second thread. */
pd->header.multiple_threads = 1;
-#ifndef TLS_MULTIPLE_THREADS_IN_TCB
- __libc_multiple_threads = 1;
-#endif
#ifdef NEED_DL_SYSINFO
SETUP_THREAD_SYSINFO (pd);
@@ -413,9 +410,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
/* This is at least the second thread. */
pd->header.multiple_threads = 1;
-#ifndef TLS_MULTIPLE_THREADS_IN_TCB
- __libc_multiple_threads = 1;
-#endif
#ifdef NEED_DL_SYSINFO
SETUP_THREAD_SYSINFO (pd);
diff --git a/nptl/libc_multiple_threads.c b/nptl/libc_multiple_threads.c
deleted file mode 100644
index 0c2dc33d0d..0000000000
--- a/nptl/libc_multiple_threads.c
+++ /dev/null
@@ -1,28 +0,0 @@
-/* Copyright (C) 2002-2022 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#include <pthreadP.h>
-
-#if IS_IN (libc)
-# ifndef TLS_MULTIPLE_THREADS_IN_TCB
-/* Variable set to a nonzero value either if more than one thread runs or ran,
- or if a single-threaded process is trying to cancel itself. See
- nptl/descr.h for more context on the single-threaded process case. */
-int __libc_multiple_threads;
-libc_hidden_data_def (__libc_multiple_threads)
-# endif
-#endif
diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c
index e67b2df5cc..459317df49 100644
--- a/nptl/pthread_cancel.c
+++ b/nptl/pthread_cancel.c
@@ -161,7 +161,7 @@ __pthread_cancel (pthread_t th)
points get executed. */
THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
#ifndef TLS_MULTIPLE_THREADS_IN_TCB
- __libc_multiple_threads = 1;
+ __libc_single_threaded_internal = 0;
#endif
}
while (!atomic_compare_exchange_weak_acquire (&pd->cancelhandling, &oldval,
diff --git a/posix/fork.c b/posix/fork.c
index 987916a175..cee5ae83c8 100644
--- a/posix/fork.c
+++ b/posix/fork.c
@@ -45,7 +45,7 @@ __libc_fork (void)
requirement for fork (Austin Group tracker issue #62) this is
best effort to make is async-signal-safe at least for single-thread
case. */
- bool multiple_threads = __libc_single_threaded_internal == 0;
+ bool multiple_threads = !SINGLE_THREAD_P;
uint64_t lastrun;
lastrun = __run_prefork_handlers (multiple_threads);
diff --git a/sysdeps/nptl/setxid.h b/sysdeps/nptl/setxid.h
index b87cad7b18..3a412179ac 100644
--- a/sysdeps/nptl/setxid.h
+++ b/sysdeps/nptl/setxid.h
@@ -29,7 +29,7 @@
#define INLINE_SETXID_SYSCALL(name, nr, args...) \
({ \
int __result; \
- if (!__libc_single_threaded_internal) \
+ if (!SINGLE_THREAD_P) \
{ \
struct xid_command __cmd; \
__cmd.syscall_no = __NR_##name; \
diff --git a/sysdeps/unix/sysv/linux/aarch64/single-thread.h b/sysdeps/unix/sysv/linux/aarch64/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/aarch64/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/aarch64/sysdep.h b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
index 3b230dccf1..f1853e012f 100644
--- a/sysdeps/unix/sysv/linux/aarch64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
@@ -164,8 +164,6 @@
# define HAVE_CLOCK_GETTIME64_VSYSCALL "__kernel_clock_gettime"
# define HAVE_GETTIMEOFDAY_VSYSCALL "__kernel_gettimeofday"
-# define SINGLE_THREAD_BY_GLOBAL 1
-
# undef INTERNAL_SYSCALL_RAW
# define INTERNAL_SYSCALL_RAW(name, nr, args...) \
({ long _sys_result; \
diff --git a/sysdeps/unix/sysv/linux/alpha/sysdep.h b/sysdeps/unix/sysv/linux/alpha/sysdep.h
index 3051a744b4..77ec2b5400 100644
--- a/sysdeps/unix/sysv/linux/alpha/sysdep.h
+++ b/sysdeps/unix/sysv/linux/alpha/sysdep.h
@@ -32,8 +32,6 @@
#undef SYS_ify
#define SYS_ify(syscall_name) __NR_##syscall_name
-#define SINGLE_THREAD_BY_GLOBAL 1
-
#ifdef __ASSEMBLER__
#include <asm/pal.h>
#include <alpha/regdef.h>
diff --git a/sysdeps/unix/sysv/linux/arc/single-thread.h b/sysdeps/unix/sysv/linux/arc/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arc/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/arc/sysdep.h b/sysdeps/unix/sysv/linux/arc/sysdep.h
index 29b0e0161c..d0c1a78381 100644
--- a/sysdeps/unix/sysv/linux/arc/sysdep.h
+++ b/sysdeps/unix/sysv/linux/arc/sysdep.h
@@ -132,8 +132,6 @@ L (call_syscall_err): ASM_LINE_SEP \
#else /* !__ASSEMBLER__ */
-# define SINGLE_THREAD_BY_GLOBAL 1
-
# if IS_IN (libc)
extern long int __syscall_error (long int);
hidden_proto (__syscall_error)
diff --git a/sysdeps/unix/sysv/linux/arm/single-thread.h b/sysdeps/unix/sysv/linux/arm/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arm/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/arm/sysdep.h b/sysdeps/unix/sysv/linux/arm/sysdep.h
index 7bdd218063..1f270b961e 100644
--- a/sysdeps/unix/sysv/linux/arm/sysdep.h
+++ b/sysdeps/unix/sysv/linux/arm/sysdep.h
@@ -408,8 +408,6 @@ __local_syscall_error: \
#define INTERNAL_SYSCALL_NCS(number, nr, args...) \
INTERNAL_SYSCALL_RAW (number, nr, args)
-#define SINGLE_THREAD_BY_GLOBAL 1
-
#endif /* __ASSEMBLER__ */
#endif /* linux/arm/sysdep.h */
diff --git a/sysdeps/unix/sysv/linux/hppa/single-thread.h b/sysdeps/unix/sysv/linux/hppa/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/hppa/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/hppa/sysdep.h b/sysdeps/unix/sysv/linux/hppa/sysdep.h
index 42f7705852..2f339a4bd6 100644
--- a/sysdeps/unix/sysv/linux/hppa/sysdep.h
+++ b/sysdeps/unix/sysv/linux/hppa/sysdep.h
@@ -474,6 +474,4 @@ L(pre_end): ASM_LINE_SEP \
#define PTR_MANGLE(var) (void) (var)
#define PTR_DEMANGLE(var) (void) (var)
-#define SINGLE_THREAD_BY_GLOBAL 1
-
#endif /* _LINUX_HPPA_SYSDEP_H */
diff --git a/sysdeps/unix/sysv/linux/microblaze/single-thread.h b/sysdeps/unix/sysv/linux/microblaze/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/microblaze/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/microblaze/sysdep.h b/sysdeps/unix/sysv/linux/microblaze/sysdep.h
index dfd6312506..fda78f6467 100644
--- a/sysdeps/unix/sysv/linux/microblaze/sysdep.h
+++ b/sysdeps/unix/sysv/linux/microblaze/sysdep.h
@@ -308,8 +308,6 @@ SYSCALL_ERROR_LABEL_DCL: \
# define PTR_MANGLE(var) (void) (var)
# define PTR_DEMANGLE(var) (void) (var)
-# define SINGLE_THREAD_BY_GLOBAL 1
-
#undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
#define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
diff --git a/sysdeps/unix/sysv/linux/s390/single-thread.h b/sysdeps/unix/sysv/linux/s390/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/s390/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/s390/sysdep.h b/sysdeps/unix/sysv/linux/s390/sysdep.h
index 78c7e8c7e2..2d0a26779c 100644
--- a/sysdeps/unix/sysv/linux/s390/sysdep.h
+++ b/sysdeps/unix/sysv/linux/s390/sysdep.h
@@ -93,9 +93,6 @@
#define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
#define ASMFMT_6 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6), "d" (gpr7)
-#define SINGLE_THREAD_BY_GLOBAL 1
-
-
#define VDSO_NAME "LINUX_2.6.29"
#define VDSO_HASH 123718585
diff --git a/sysdeps/unix/sysv/linux/single-thread.h b/sysdeps/unix/sysv/linux/single-thread.h
index 4529a906d2..30dde4e81a 100644
--- a/sysdeps/unix/sysv/linux/single-thread.h
+++ b/sysdeps/unix/sysv/linux/single-thread.h
@@ -19,6 +19,10 @@
#ifndef _SINGLE_THREAD_H
#define _SINGLE_THREAD_H
+#ifndef __ASSEMBLER__
+# include <sys/single_threaded.h>
+#endif
+
/* The default way to check if the process is single thread is by using the
pthread_t 'multiple_threads' field. However, for some architectures it is
faster to either use an extra field on TCB or global variables (the TCB
@@ -27,16 +31,11 @@
The ABI might define SINGLE_THREAD_BY_GLOBAL to enable the single thread
check to use global variables instead of the pthread_t field. */
-#ifndef __ASSEMBLER__
-extern int __libc_multiple_threads;
-libc_hidden_proto (__libc_multiple_threads)
-#endif
-
#if !defined SINGLE_THREAD_BY_GLOBAL || IS_IN (rtld)
# define SINGLE_THREAD_P \
(THREAD_GETMEM (THREAD_SELF, header.multiple_threads) == 0)
#else
-# define SINGLE_THREAD_P (__libc_multiple_threads == 0)
+# define SINGLE_THREAD_P (__libc_single_threaded_internal != 0)
#endif
#define RTLD_SINGLE_THREAD_P SINGLE_THREAD_P
diff --git a/sysdeps/unix/sysv/linux/x86_64/single-thread.h b/sysdeps/unix/sysv/linux/x86_64/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86_64/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/x86_64/sysdep.h b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
index e1ce3b62eb..740abefcfd 100644
--- a/sysdeps/unix/sysv/linux/x86_64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
@@ -379,8 +379,6 @@
# define HAVE_CLONE3_WRAPPER 1
-# define SINGLE_THREAD_BY_GLOBAL 1
-
#endif /* __ASSEMBLER__ */
--
2.34.1
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v3 3/4] Remove usage of TLS_MULTIPLE_THREADS_IN_TCB
2022-06-21 20:32 [PATCH v3 0/4] Simplify internal single-threaded usage Adhemerval Zanella
2022-06-21 20:32 ` [PATCH v3 1/4] misc: Optimize internal usage of __libc_single_threaded Adhemerval Zanella
2022-06-21 20:32 ` [PATCH v3 2/4] Replace __libc_multiple_threads with __libc_single_threaded Adhemerval Zanella
@ 2022-06-21 20:32 ` Adhemerval Zanella
2022-06-21 20:32 ` [PATCH v3 4/4] Remove single-thread.h Adhemerval Zanella
3 siblings, 0 replies; 12+ messages in thread
From: Adhemerval Zanella @ 2022-06-21 20:32 UTC (permalink / raw)
To: libc-alpha, Wilco Dijkstra, Fangrui Song
Instead use __libc_single_threaded on all architectures. The TCB
field is renamed to avoid change the struct layout.
The x86 atomic need some adjustments since it has single-thread
optimizationi builtin within the inline assemblye. It now uses
SINGLE_THREAD_P and atomic optimizations are removed (since they
are not used).
Checked on x86_64-linux-gnu and i686-linux-gnu.
---
misc/tst-atomic.c | 1 +
nptl/allocatestack.c | 6 -
nptl/descr.h | 17 +-
nptl/pthread_cancel.c | 7 +-
nptl/pthread_create.c | 5 -
sysdeps/i386/htl/tcb-offsets.sym | 1 -
sysdeps/i386/nptl/tcb-offsets.sym | 1 -
sysdeps/i386/nptl/tls.h | 4 +-
sysdeps/ia64/nptl/tcb-offsets.sym | 1 -
sysdeps/ia64/nptl/tls.h | 2 -
sysdeps/mach/hurd/i386/tls.h | 4 +-
sysdeps/nios2/nptl/tcb-offsets.sym | 1 -
sysdeps/or1k/nptl/tls.h | 2 -
sysdeps/powerpc/nptl/tcb-offsets.sym | 3 -
sysdeps/powerpc/nptl/tls.h | 3 -
sysdeps/s390/nptl/tcb-offsets.sym | 1 -
sysdeps/s390/nptl/tls.h | 6 +-
sysdeps/sh/nptl/tcb-offsets.sym | 1 -
sysdeps/sh/nptl/tls.h | 2 -
sysdeps/sparc/nptl/tcb-offsets.sym | 1 -
sysdeps/sparc/nptl/tls.h | 2 +-
sysdeps/unix/sysv/linux/single-thread.h | 15 +-
sysdeps/x86/atomic-machine.h | 488 +++++++-----------------
sysdeps/x86_64/nptl/tcb-offsets.sym | 1 -
sysdeps/x86_64/nptl/tls.h | 2 +-
25 files changed, 148 insertions(+), 429 deletions(-)
diff --git a/misc/tst-atomic.c b/misc/tst-atomic.c
index 6d681a7bfd..ddbc618e25 100644
--- a/misc/tst-atomic.c
+++ b/misc/tst-atomic.c
@@ -18,6 +18,7 @@
#include <stdio.h>
#include <atomic.h>
+#include <support/xthread.h>
#ifndef atomic_t
# define atomic_t int
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c
index 98f5f6dd85..3e0d01cb52 100644
--- a/nptl/allocatestack.c
+++ b/nptl/allocatestack.c
@@ -290,9 +290,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
stack cache nor will the memory (except the TLS memory) be freed. */
pd->user_stack = true;
- /* This is at least the second thread. */
- pd->header.multiple_threads = 1;
-
#ifdef NEED_DL_SYSINFO
SETUP_THREAD_SYSINFO (pd);
#endif
@@ -408,9 +405,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
descriptor. */
pd->specific[0] = pd->specific_1stblock;
- /* This is at least the second thread. */
- pd->header.multiple_threads = 1;
-
#ifdef NEED_DL_SYSINFO
SETUP_THREAD_SYSINFO (pd);
#endif
diff --git a/nptl/descr.h b/nptl/descr.h
index bb46b5958e..77b25d8267 100644
--- a/nptl/descr.h
+++ b/nptl/descr.h
@@ -137,22 +137,7 @@ struct pthread
#else
struct
{
- /* multiple_threads is enabled either when the process has spawned at
- least one thread or when a single-threaded process cancels itself.
- This enables additional code to introduce locking before doing some
- compare_and_exchange operations and also enable cancellation points.
- The concepts of multiple threads and cancellation points ideally
- should be separate, since it is not necessary for multiple threads to
- have been created for cancellation points to be enabled, as is the
- case is when single-threaded process cancels itself.
-
- Since enabling multiple_threads enables additional code in
- cancellation points and compare_and_exchange operations, there is a
- potential for an unneeded performance hit when it is enabled in a
- single-threaded, self-canceling process. This is OK though, since a
- single-threaded process will enable async cancellation only when it
- looks to cancel itself and is hence going to end anyway. */
- int multiple_threads;
+ int unused_multiple_threads;
int gscope_flag;
} header;
#endif
diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c
index 459317df49..27dca9fe6a 100644
--- a/nptl/pthread_cancel.c
+++ b/nptl/pthread_cancel.c
@@ -157,12 +157,9 @@ __pthread_cancel (pthread_t th)
/* A single-threaded process should be able to kill itself, since
there is nothing in the POSIX specification that says that it
- cannot. So we set multiple_threads to true so that cancellation
- points get executed. */
- THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
-#ifndef TLS_MULTIPLE_THREADS_IN_TCB
+ cannot. So we set __libc_single_threaded to true so that
+ cancellation points get executed. */
__libc_single_threaded_internal = 0;
-#endif
}
while (!atomic_compare_exchange_weak_acquire (&pd->cancelhandling, &oldval,
newval));
diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index 5b98e053d6..59a0df68bc 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -881,11 +881,6 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
other reason that create_thread chose. Now let it run
free. */
lll_unlock (pd->lock, LLL_PRIVATE);
-
- /* We now have for sure more than one thread. The main thread might
- not yet have the flag set. No need to set the global variable
- again if this is what we use. */
- THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
}
out:
diff --git a/sysdeps/i386/htl/tcb-offsets.sym b/sysdeps/i386/htl/tcb-offsets.sym
index 7b7c719369..f3f7df6c06 100644
--- a/sysdeps/i386/htl/tcb-offsets.sym
+++ b/sysdeps/i386/htl/tcb-offsets.sym
@@ -2,7 +2,6 @@
#include <tls.h>
#include <kernel-features.h>
-MULTIPLE_THREADS_OFFSET offsetof (tcbhead_t, multiple_threads)
SYSINFO_OFFSET offsetof (tcbhead_t, sysinfo)
POINTER_GUARD offsetof (tcbhead_t, pointer_guard)
SIGSTATE_OFFSET offsetof (tcbhead_t, _hurd_sigstate)
diff --git a/sysdeps/i386/nptl/tcb-offsets.sym b/sysdeps/i386/nptl/tcb-offsets.sym
index 2ec9e787c1..1efd1469d8 100644
--- a/sysdeps/i386/nptl/tcb-offsets.sym
+++ b/sysdeps/i386/nptl/tcb-offsets.sym
@@ -6,7 +6,6 @@ RESULT offsetof (struct pthread, result)
TID offsetof (struct pthread, tid)
CANCELHANDLING offsetof (struct pthread, cancelhandling)
CLEANUP_JMP_BUF offsetof (struct pthread, cleanup_jmp_buf)
-MULTIPLE_THREADS_OFFSET offsetof (tcbhead_t, multiple_threads)
SYSINFO_OFFSET offsetof (tcbhead_t, sysinfo)
CLEANUP offsetof (struct pthread, cleanup)
CLEANUP_PREV offsetof (struct _pthread_cleanup_buffer, __prev)
diff --git a/sysdeps/i386/nptl/tls.h b/sysdeps/i386/nptl/tls.h
index 91090bf287..48940a9f44 100644
--- a/sysdeps/i386/nptl/tls.h
+++ b/sysdeps/i386/nptl/tls.h
@@ -36,7 +36,7 @@ typedef struct
thread descriptor used by libpthread. */
dtv_t *dtv;
void *self; /* Pointer to the thread descriptor. */
- int multiple_threads;
+ int unused_multiple_threads;
uintptr_t sysinfo;
uintptr_t stack_guard;
uintptr_t pointer_guard;
@@ -57,8 +57,6 @@ typedef struct
_Static_assert (offsetof (tcbhead_t, __private_ss) == 0x30,
"offset of __private_ss != 0x30");
-# define TLS_MULTIPLE_THREADS_IN_TCB 1
-
#else /* __ASSEMBLER__ */
# include <tcb-offsets.h>
#endif
diff --git a/sysdeps/ia64/nptl/tcb-offsets.sym b/sysdeps/ia64/nptl/tcb-offsets.sym
index b01f712be2..ab2cb180f9 100644
--- a/sysdeps/ia64/nptl/tcb-offsets.sym
+++ b/sysdeps/ia64/nptl/tcb-offsets.sym
@@ -2,5 +2,4 @@
#include <tls.h>
TID offsetof (struct pthread, tid) - TLS_PRE_TCB_SIZE
-MULTIPLE_THREADS_OFFSET offsetof (struct pthread, header.multiple_threads) - TLS_PRE_TCB_SIZE
SYSINFO_OFFSET offsetof (tcbhead_t, __private)
diff --git a/sysdeps/ia64/nptl/tls.h b/sysdeps/ia64/nptl/tls.h
index 8ccedb73e6..008e080fc4 100644
--- a/sysdeps/ia64/nptl/tls.h
+++ b/sysdeps/ia64/nptl/tls.h
@@ -36,8 +36,6 @@ typedef struct
register struct pthread *__thread_self __asm__("r13");
-# define TLS_MULTIPLE_THREADS_IN_TCB 1
-
#else /* __ASSEMBLER__ */
# include <tcb-offsets.h>
#endif
diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h
index 264ed9a9c5..d33e91c922 100644
--- a/sysdeps/mach/hurd/i386/tls.h
+++ b/sysdeps/mach/hurd/i386/tls.h
@@ -33,7 +33,7 @@ typedef struct
void *tcb; /* Points to this structure. */
dtv_t *dtv; /* Vector of pointers to TLS data. */
thread_t self; /* This thread's control port. */
- int multiple_threads;
+ int unused_multiple_threads;
uintptr_t sysinfo;
uintptr_t stack_guard;
uintptr_t pointer_guard;
@@ -117,8 +117,6 @@ _hurd_tls_init (tcbhead_t *tcb)
/* This field is used by TLS accesses to get our "thread pointer"
from the TLS point of view. */
tcb->tcb = tcb;
- /* We always at least start the sigthread anyway. */
- tcb->multiple_threads = 1;
/* Get the first available selector. */
int sel = -1;
diff --git a/sysdeps/nios2/nptl/tcb-offsets.sym b/sysdeps/nios2/nptl/tcb-offsets.sym
index 3cd8d984ac..93a695ac7f 100644
--- a/sysdeps/nios2/nptl/tcb-offsets.sym
+++ b/sysdeps/nios2/nptl/tcb-offsets.sym
@@ -8,6 +8,5 @@
# define __thread_self ((void *) 0)
# define thread_offsetof(mem) ((ptrdiff_t) THREAD_SELF + offsetof (struct pthread, mem))
-MULTIPLE_THREADS_OFFSET thread_offsetof (header.multiple_threads)
TID_OFFSET thread_offsetof (tid)
POINTER_GUARD (offsetof (tcbhead_t, pointer_guard) - TLS_TCB_OFFSET - sizeof (tcbhead_t))
diff --git a/sysdeps/or1k/nptl/tls.h b/sysdeps/or1k/nptl/tls.h
index c6ffe62c3f..3bb07beef8 100644
--- a/sysdeps/or1k/nptl/tls.h
+++ b/sysdeps/or1k/nptl/tls.h
@@ -35,8 +35,6 @@ typedef struct
register tcbhead_t *__thread_self __asm__("r10");
-# define TLS_MULTIPLE_THREADS_IN_TCB 1
-
/* Get system call information. */
# include <sysdep.h>
diff --git a/sysdeps/powerpc/nptl/tcb-offsets.sym b/sysdeps/powerpc/nptl/tcb-offsets.sym
index 4c01615ad0..a0ee95f94d 100644
--- a/sysdeps/powerpc/nptl/tcb-offsets.sym
+++ b/sysdeps/powerpc/nptl/tcb-offsets.sym
@@ -10,9 +10,6 @@
# define thread_offsetof(mem) ((ptrdiff_t) THREAD_SELF + offsetof (struct pthread, mem))
-#if TLS_MULTIPLE_THREADS_IN_TCB
-MULTIPLE_THREADS_OFFSET thread_offsetof (header.multiple_threads)
-#endif
TID thread_offsetof (tid)
POINTER_GUARD (offsetof (tcbhead_t, pointer_guard) - TLS_TCB_OFFSET - sizeof (tcbhead_t))
TAR_SAVE (offsetof (tcbhead_t, tar_save) - TLS_TCB_OFFSET - sizeof (tcbhead_t))
diff --git a/sysdeps/powerpc/nptl/tls.h b/sysdeps/powerpc/nptl/tls.h
index 22b0075235..fd5ee51981 100644
--- a/sysdeps/powerpc/nptl/tls.h
+++ b/sysdeps/powerpc/nptl/tls.h
@@ -52,9 +52,6 @@
# define TLS_DTV_AT_TP 1
# define TLS_TCB_AT_TP 0
-/* We use the multiple_threads field in the pthread struct */
-#define TLS_MULTIPLE_THREADS_IN_TCB 1
-
/* Get the thread descriptor definition. */
# include <nptl/descr.h>
diff --git a/sysdeps/s390/nptl/tcb-offsets.sym b/sysdeps/s390/nptl/tcb-offsets.sym
index 9c1c01f353..bc7b267463 100644
--- a/sysdeps/s390/nptl/tcb-offsets.sym
+++ b/sysdeps/s390/nptl/tcb-offsets.sym
@@ -1,6 +1,5 @@
#include <sysdep.h>
#include <tls.h>
-MULTIPLE_THREADS_OFFSET offsetof (tcbhead_t, multiple_threads)
STACK_GUARD offsetof (tcbhead_t, stack_guard)
TID offsetof (struct pthread, tid)
diff --git a/sysdeps/s390/nptl/tls.h b/sysdeps/s390/nptl/tls.h
index ff210ffeb2..d69ed539f7 100644
--- a/sysdeps/s390/nptl/tls.h
+++ b/sysdeps/s390/nptl/tls.h
@@ -35,7 +35,7 @@ typedef struct
thread descriptor used by libpthread. */
dtv_t *dtv;
void *self; /* Pointer to the thread descriptor. */
- int multiple_threads;
+ int unused_multiple_threads;
uintptr_t sysinfo;
uintptr_t stack_guard;
int gscope_flag;
@@ -44,10 +44,6 @@ typedef struct
void *__private_ss;
} tcbhead_t;
-# ifndef __s390x__
-# define TLS_MULTIPLE_THREADS_IN_TCB 1
-# endif
-
#else /* __ASSEMBLER__ */
# include <tcb-offsets.h>
#endif
diff --git a/sysdeps/sh/nptl/tcb-offsets.sym b/sysdeps/sh/nptl/tcb-offsets.sym
index 234207779d..4e452d9c6c 100644
--- a/sysdeps/sh/nptl/tcb-offsets.sym
+++ b/sysdeps/sh/nptl/tcb-offsets.sym
@@ -6,7 +6,6 @@ RESULT offsetof (struct pthread, result)
TID offsetof (struct pthread, tid)
CANCELHANDLING offsetof (struct pthread, cancelhandling)
CLEANUP_JMP_BUF offsetof (struct pthread, cleanup_jmp_buf)
-MULTIPLE_THREADS_OFFSET offsetof (struct pthread, header.multiple_threads)
TLS_PRE_TCB_SIZE sizeof (struct pthread)
MUTEX_FUTEX offsetof (pthread_mutex_t, __data.__lock)
POINTER_GUARD offsetof (tcbhead_t, pointer_guard)
diff --git a/sysdeps/sh/nptl/tls.h b/sysdeps/sh/nptl/tls.h
index 76591ab6ef..8778cb4ac0 100644
--- a/sysdeps/sh/nptl/tls.h
+++ b/sysdeps/sh/nptl/tls.h
@@ -36,8 +36,6 @@ typedef struct
uintptr_t pointer_guard;
} tcbhead_t;
-# define TLS_MULTIPLE_THREADS_IN_TCB 1
-
#else /* __ASSEMBLER__ */
# include <tcb-offsets.h>
#endif /* __ASSEMBLER__ */
diff --git a/sysdeps/sparc/nptl/tcb-offsets.sym b/sysdeps/sparc/nptl/tcb-offsets.sym
index f75d02065e..e4a7e4720f 100644
--- a/sysdeps/sparc/nptl/tcb-offsets.sym
+++ b/sysdeps/sparc/nptl/tcb-offsets.sym
@@ -1,6 +1,5 @@
#include <sysdep.h>
#include <tls.h>
-MULTIPLE_THREADS_OFFSET offsetof (tcbhead_t, multiple_threads)
POINTER_GUARD offsetof (tcbhead_t, pointer_guard)
TID offsetof (struct pthread, tid)
diff --git a/sysdeps/sparc/nptl/tls.h b/sysdeps/sparc/nptl/tls.h
index d1e2bb4ad1..b78cf0d6b4 100644
--- a/sysdeps/sparc/nptl/tls.h
+++ b/sysdeps/sparc/nptl/tls.h
@@ -35,7 +35,7 @@ typedef struct
thread descriptor used by libpthread. */
dtv_t *dtv;
void *self;
- int multiple_threads;
+ int unused_multiple_threads;
#if __WORDSIZE == 64
int gscope_flag;
#endif
diff --git a/sysdeps/unix/sysv/linux/single-thread.h b/sysdeps/unix/sysv/linux/single-thread.h
index 30dde4e81a..2099848cf3 100644
--- a/sysdeps/unix/sysv/linux/single-thread.h
+++ b/sysdeps/unix/sysv/linux/single-thread.h
@@ -23,20 +23,7 @@
# include <sys/single_threaded.h>
#endif
-/* The default way to check if the process is single thread is by using the
- pthread_t 'multiple_threads' field. However, for some architectures it is
- faster to either use an extra field on TCB or global variables (the TCB
- field is also used on x86 for some single-thread atomic optimizations).
-
- The ABI might define SINGLE_THREAD_BY_GLOBAL to enable the single thread
- check to use global variables instead of the pthread_t field. */
-
-#if !defined SINGLE_THREAD_BY_GLOBAL || IS_IN (rtld)
-# define SINGLE_THREAD_P \
- (THREAD_GETMEM (THREAD_SELF, header.multiple_threads) == 0)
-#else
-# define SINGLE_THREAD_P (__libc_single_threaded_internal != 0)
-#endif
+#define SINGLE_THREAD_P (__libc_single_threaded_internal != 0)
#define RTLD_SINGLE_THREAD_P SINGLE_THREAD_P
diff --git a/sysdeps/x86/atomic-machine.h b/sysdeps/x86/atomic-machine.h
index f24f1c71ed..2db69d2d5d 100644
--- a/sysdeps/x86/atomic-machine.h
+++ b/sysdeps/x86/atomic-machine.h
@@ -51,292 +51,145 @@
#define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
(! __sync_bool_compare_and_swap (mem, oldval, newval))
-
-#define __arch_c_compare_and_exchange_val_8_acq(mem, newval, oldval) \
- ({ __typeof (*mem) ret; \
- __asm __volatile ("cmpl $0, %%" SEG_REG ":%P5\n\t" \
- "je 0f\n\t" \
- "lock\n" \
- "0:\tcmpxchgb %b2, %1" \
- : "=a" (ret), "=m" (*mem) \
- : BR_CONSTRAINT (newval), "m" (*mem), "0" (oldval), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- ret; })
-
-#define __arch_c_compare_and_exchange_val_16_acq(mem, newval, oldval) \
- ({ __typeof (*mem) ret; \
- __asm __volatile ("cmpl $0, %%" SEG_REG ":%P5\n\t" \
- "je 0f\n\t" \
- "lock\n" \
- "0:\tcmpxchgw %w2, %1" \
- : "=a" (ret), "=m" (*mem) \
- : BR_CONSTRAINT (newval), "m" (*mem), "0" (oldval), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- ret; })
-
-#define __arch_c_compare_and_exchange_val_32_acq(mem, newval, oldval) \
- ({ __typeof (*mem) ret; \
- __asm __volatile ("cmpl $0, %%" SEG_REG ":%P5\n\t" \
- "je 0f\n\t" \
- "lock\n" \
- "0:\tcmpxchgl %2, %1" \
- : "=a" (ret), "=m" (*mem) \
- : BR_CONSTRAINT (newval), "m" (*mem), "0" (oldval), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- ret; })
-
-#ifdef __x86_64__
-# define __arch_c_compare_and_exchange_val_64_acq(mem, newval, oldval) \
- ({ __typeof (*mem) ret; \
- __asm __volatile ("cmpl $0, %%fs:%P5\n\t" \
- "je 0f\n\t" \
- "lock\n" \
- "0:\tcmpxchgq %q2, %1" \
- : "=a" (ret), "=m" (*mem) \
- : "q" ((int64_t) cast_to_integer (newval)), \
- "m" (*mem), \
- "0" ((int64_t) cast_to_integer (oldval)), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- ret; })
-# define do_exchange_and_add_val_64_acq(pfx, mem, value) 0
-# define do_add_val_64_acq(pfx, mem, value) do { } while (0)
-#else
-/* XXX We do not really need 64-bit compare-and-exchange. At least
- not in the moment. Using it would mean causing portability
- problems since not many other 32-bit architectures have support for
- such an operation. So don't define any code for now. If it is
- really going to be used the code below can be used on Intel Pentium
- and later, but NOT on i486. */
-# define __arch_c_compare_and_exchange_val_64_acq(mem, newval, oldval) \
- ({ __typeof (*mem) ret = *(mem); \
- __atomic_link_error (); \
- ret = (newval); \
- ret = (oldval); \
- ret; })
-
-# define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \
- ({ __typeof (*mem) ret = *(mem); \
- __atomic_link_error (); \
- ret = (newval); \
- ret = (oldval); \
- ret; })
-
-# define do_exchange_and_add_val_64_acq(pfx, mem, value) \
- ({ __typeof (value) __addval = (value); \
- __typeof (*mem) __result; \
- __typeof (mem) __memp = (mem); \
- __typeof (*mem) __tmpval; \
- __result = *__memp; \
- do \
- __tmpval = __result; \
- while ((__result = pfx##_compare_and_exchange_val_64_acq \
- (__memp, __result + __addval, __result)) == __tmpval); \
- __result; })
-
-# define do_add_val_64_acq(pfx, mem, value) \
- { \
- __typeof (value) __addval = (value); \
- __typeof (mem) __memp = (mem); \
- __typeof (*mem) __oldval = *__memp; \
- __typeof (*mem) __tmpval; \
- do \
- __tmpval = __oldval; \
- while ((__oldval = pfx##_compare_and_exchange_val_64_acq \
- (__memp, __oldval + __addval, __oldval)) == __tmpval); \
- }
-#endif
-
-
-/* Note that we need no lock prefix. */
-#define atomic_exchange_acq(mem, newvalue) \
- ({ __typeof (*mem) result; \
+#define __cmpxchg_op(lock, mem, newval, oldval) \
+ ({ __typeof (*mem) __ret; \
if (sizeof (*mem) == 1) \
- __asm __volatile ("xchgb %b0, %1" \
- : "=q" (result), "=m" (*mem) \
- : "0" (newvalue), "m" (*mem)); \
+ asm volatile (lock "cmpxchgb %2, %1" \
+ : "=a" (__ret), "+m" (*mem) \
+ : BR_CONSTRAINT (newval), "0" (oldval) \
+ : "memory"); \
else if (sizeof (*mem) == 2) \
- __asm __volatile ("xchgw %w0, %1" \
- : "=r" (result), "=m" (*mem) \
- : "0" (newvalue), "m" (*mem)); \
+ asm volatile (lock "cmpxchgw %2, %1" \
+ : "=a" (__ret), "+m" (*mem) \
+ : BR_CONSTRAINT (newval), "0" (oldval) \
+ : "memory"); \
else if (sizeof (*mem) == 4) \
- __asm __volatile ("xchgl %0, %1" \
- : "=r" (result), "=m" (*mem) \
- : "0" (newvalue), "m" (*mem)); \
+ asm volatile (lock "cmpxchgl %2, %1" \
+ : "=a" (__ret), "+m" (*mem) \
+ : BR_CONSTRAINT (newval), "0" (oldval) \
+ : "memory"); \
else if (__HAVE_64B_ATOMICS) \
- __asm __volatile ("xchgq %q0, %1" \
- : "=r" (result), "=m" (*mem) \
- : "0" ((int64_t) cast_to_integer (newvalue)), \
- "m" (*mem)); \
+ asm volatile (lock "cmpxchgq %2, %1" \
+ : "=a" (__ret), "+m" (*mem) \
+ : "q" ((int64_t) cast_to_integer (newval)), \
+ "0" ((int64_t) cast_to_integer (oldval)) \
+ : "memory"); \
else \
- { \
- result = 0; \
- __atomic_link_error (); \
- } \
- result; })
-
+ __atomic_link_error (); \
+ __ret; })
-#define __arch_exchange_and_add_body(lock, pfx, mem, value) \
- ({ __typeof (*mem) __result; \
- __typeof (value) __addval = (value); \
- if (sizeof (*mem) == 1) \
- __asm __volatile (lock "xaddb %b0, %1" \
- : "=q" (__result), "=m" (*mem) \
- : "0" (__addval), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (sizeof (*mem) == 2) \
- __asm __volatile (lock "xaddw %w0, %1" \
- : "=r" (__result), "=m" (*mem) \
- : "0" (__addval), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (sizeof (*mem) == 4) \
- __asm __volatile (lock "xaddl %0, %1" \
- : "=r" (__result), "=m" (*mem) \
- : "0" (__addval), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (__HAVE_64B_ATOMICS) \
- __asm __volatile (lock "xaddq %q0, %1" \
- : "=r" (__result), "=m" (*mem) \
- : "0" ((int64_t) cast_to_integer (__addval)), \
- "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
+#define __arch_c_compare_and_exchange_val_8_acq(mem, newval, oldval) \
+ ({ __typeof (*mem) __ret; \
+ if (SINGLE_THREAD_P) \
+ __ret = __cmpxchg_op ("", (mem), (newval), (oldval)); \
else \
- __result = do_exchange_and_add_val_64_acq (pfx, (mem), __addval); \
- __result; })
-
-#define atomic_exchange_and_add(mem, value) \
- __sync_fetch_and_add (mem, value)
-
-#define __arch_exchange_and_add_cprefix \
- "cmpl $0, %%" SEG_REG ":%P4\n\tje 0f\n\tlock\n0:\t"
-
-#define catomic_exchange_and_add(mem, value) \
- __arch_exchange_and_add_body (__arch_exchange_and_add_cprefix, __arch_c, \
- mem, value)
+ __ret = __cmpxchg_op (LOCK_PREFIX, (mem), (newval), (oldval)); \
+ __ret; })
+#define __arch_c_compare_and_exchange_val_16_acq(mem, newval, oldval) \
+ ({ __typeof (*mem) __ret; \
+ if (SINGLE_THREAD_P) \
+ __ret = __cmpxchg_op ("", (mem), (newval), (oldval)); \
+ else \
+ __ret = __cmpxchg_op (LOCK_PREFIX, (mem), (newval), (oldval)); \
+ __ret; })
-#define __arch_add_body(lock, pfx, apfx, mem, value) \
- do { \
- if (__builtin_constant_p (value) && (value) == 1) \
- pfx##_increment (mem); \
- else if (__builtin_constant_p (value) && (value) == -1) \
- pfx##_decrement (mem); \
- else if (sizeof (*mem) == 1) \
- __asm __volatile (lock "addb %b1, %0" \
- : "=m" (*mem) \
- : IBR_CONSTRAINT (value), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (sizeof (*mem) == 2) \
- __asm __volatile (lock "addw %w1, %0" \
- : "=m" (*mem) \
- : "ir" (value), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (sizeof (*mem) == 4) \
- __asm __volatile (lock "addl %1, %0" \
- : "=m" (*mem) \
- : "ir" (value), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (__HAVE_64B_ATOMICS) \
- __asm __volatile (lock "addq %q1, %0" \
- : "=m" (*mem) \
- : "ir" ((int64_t) cast_to_integer (value)), \
- "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else \
- do_add_val_64_acq (apfx, (mem), (value)); \
- } while (0)
-
-# define atomic_add(mem, value) \
- __arch_add_body (LOCK_PREFIX, atomic, __arch, mem, value)
-
-#define __arch_add_cprefix \
- "cmpl $0, %%" SEG_REG ":%P3\n\tje 0f\n\tlock\n0:\t"
+#define __arch_c_compare_and_exchange_val_32_acq(mem, newval, oldval) \
+ ({ __typeof (*mem) __ret; \
+ if (SINGLE_THREAD_P) \
+ __ret = __cmpxchg_op ("", (mem), (newval), (oldval)); \
+ else \
+ __ret = __cmpxchg_op (LOCK_PREFIX, (mem), (newval), (oldval)); \
+ __ret; })
-#define catomic_add(mem, value) \
- __arch_add_body (__arch_add_cprefix, atomic, __arch_c, mem, value)
+#define __arch_c_compare_and_exchange_val_64_acq(mem, newval, oldval) \
+ ({ __typeof (*mem) __ret; \
+ if (SINGLE_THREAD_P) \
+ __ret = __cmpxchg_op ("", (mem), (newval), (oldval)); \
+ else \
+ __ret =__cmpxchg_op (LOCK_PREFIX, (mem), (newval), (oldval)); \
+ __ret; })
-#define atomic_add_negative(mem, value) \
- ({ unsigned char __result; \
+#define __xchg_op(lock, mem, arg, op) \
+ ({ __typeof (*mem) __ret = (arg); \
if (sizeof (*mem) == 1) \
- __asm __volatile (LOCK_PREFIX "addb %b2, %0; sets %1" \
- : "=m" (*mem), "=qm" (__result) \
- : IBR_CONSTRAINT (value), "m" (*mem)); \
+ __asm __volatile (lock #op "b %b0, %1" \
+ : "=q" (__ret), "=m" (*mem) \
+ : "0" (arg), "m" (*mem) \
+ : "memory", "cc"); \
else if (sizeof (*mem) == 2) \
- __asm __volatile (LOCK_PREFIX "addw %w2, %0; sets %1" \
- : "=m" (*mem), "=qm" (__result) \
- : "ir" (value), "m" (*mem)); \
+ __asm __volatile (lock #op "w %w0, %1" \
+ : "=r" (__ret), "=m" (*mem) \
+ : "0" (arg), "m" (*mem) \
+ : "memory", "cc"); \
else if (sizeof (*mem) == 4) \
- __asm __volatile (LOCK_PREFIX "addl %2, %0; sets %1" \
- : "=m" (*mem), "=qm" (__result) \
- : "ir" (value), "m" (*mem)); \
+ __asm __volatile (lock #op "l %0, %1" \
+ : "=r" (__ret), "=m" (*mem) \
+ : "0" (arg), "m" (*mem) \
+ : "memory", "cc"); \
else if (__HAVE_64B_ATOMICS) \
- __asm __volatile (LOCK_PREFIX "addq %q2, %0; sets %1" \
- : "=m" (*mem), "=qm" (__result) \
- : "ir" ((int64_t) cast_to_integer (value)), \
- "m" (*mem)); \
+ __asm __volatile (lock #op "q %q0, %1" \
+ : "=r" (__ret), "=m" (*mem) \
+ : "0" ((int64_t) cast_to_integer (arg)), \
+ "m" (*mem) \
+ : "memory", "cc"); \
else \
__atomic_link_error (); \
- __result; })
+ __ret; })
-
-#define atomic_add_zero(mem, value) \
- ({ unsigned char __result; \
+#define __single_op(lock, mem, op) \
+ ({ \
if (sizeof (*mem) == 1) \
- __asm __volatile (LOCK_PREFIX "addb %b2, %0; setz %1" \
- : "=m" (*mem), "=qm" (__result) \
- : IBR_CONSTRAINT (value), "m" (*mem)); \
+ __asm __volatile (lock #op "b %b0" \
+ : "=m" (*mem) \
+ : "m" (*mem) \
+ : "memory", "cc"); \
else if (sizeof (*mem) == 2) \
- __asm __volatile (LOCK_PREFIX "addw %w2, %0; setz %1" \
- : "=m" (*mem), "=qm" (__result) \
- : "ir" (value), "m" (*mem)); \
+ __asm __volatile (lock #op "w %b0" \
+ : "=m" (*mem) \
+ : "m" (*mem) \
+ : "memory", "cc"); \
else if (sizeof (*mem) == 4) \
- __asm __volatile (LOCK_PREFIX "addl %2, %0; setz %1" \
- : "=m" (*mem), "=qm" (__result) \
- : "ir" (value), "m" (*mem)); \
+ __asm __volatile (lock #op "l %b0" \
+ : "=m" (*mem) \
+ : "m" (*mem) \
+ : "memory", "cc"); \
else if (__HAVE_64B_ATOMICS) \
- __asm __volatile (LOCK_PREFIX "addq %q2, %0; setz %1" \
- : "=m" (*mem), "=qm" (__result) \
- : "ir" ((int64_t) cast_to_integer (value)), \
- "m" (*mem)); \
+ __asm __volatile (lock #op "q %b0" \
+ : "=m" (*mem) \
+ : "m" (*mem) \
+ : "memory", "cc"); \
else \
- __atomic_link_error (); \
- __result; })
+ __atomic_link_error (); \
+ })
+/* Note that we need no lock prefix. */
+#define atomic_exchange_acq(mem, newvalue) \
+ __xchg_op ("", (mem), (newvalue), xchg)
-#define __arch_increment_body(lock, pfx, mem) \
- do { \
- if (sizeof (*mem) == 1) \
- __asm __volatile (lock "incb %b0" \
- : "=m" (*mem) \
- : "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (sizeof (*mem) == 2) \
- __asm __volatile (lock "incw %w0" \
- : "=m" (*mem) \
- : "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (sizeof (*mem) == 4) \
- __asm __volatile (lock "incl %0" \
- : "=m" (*mem) \
- : "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (__HAVE_64B_ATOMICS) \
- __asm __volatile (lock "incq %q0" \
- : "=m" (*mem) \
- : "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else \
- do_add_val_64_acq (pfx, mem, 1); \
- } while (0)
+#define atomic_add(mem, value) \
+ __xchg_op (LOCK_PREFIX, (mem), (value), add); \
-#define atomic_increment(mem) __arch_increment_body (LOCK_PREFIX, __arch, mem)
+#define catomic_add(mem, value) \
+ ({ \
+ if (SINGLE_THREAD_P) \
+ __xchg_op ("", (mem), (value), add); \
+ else \
+ atomic_add (mem, value); \
+ })
-#define __arch_increment_cprefix \
- "cmpl $0, %%" SEG_REG ":%P2\n\tje 0f\n\tlock\n0:\t"
-#define catomic_increment(mem) \
- __arch_increment_body (__arch_increment_cprefix, __arch_c, mem)
+#define atomic_increment(mem) \
+ __single_op (LOCK_PREFIX, (mem), inc)
+#define catomic_increment(mem) \
+ ({ \
+ if (SINGLE_THREAD_P) \
+ __single_op ("", (mem), inc); \
+ else \
+ atomic_increment (mem); \
+ })
#define atomic_increment_and_test(mem) \
({ unsigned char __result; \
@@ -357,43 +210,20 @@
: "=m" (*mem), "=qm" (__result) \
: "m" (*mem)); \
else \
- __atomic_link_error (); \
+ __atomic_link_error (); \
__result; })
-#define __arch_decrement_body(lock, pfx, mem) \
- do { \
- if (sizeof (*mem) == 1) \
- __asm __volatile (lock "decb %b0" \
- : "=m" (*mem) \
- : "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (sizeof (*mem) == 2) \
- __asm __volatile (lock "decw %w0" \
- : "=m" (*mem) \
- : "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (sizeof (*mem) == 4) \
- __asm __volatile (lock "decl %0" \
- : "=m" (*mem) \
- : "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (__HAVE_64B_ATOMICS) \
- __asm __volatile (lock "decq %q0" \
- : "=m" (*mem) \
- : "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else \
- do_add_val_64_acq (pfx, mem, -1); \
- } while (0)
-
-#define atomic_decrement(mem) __arch_decrement_body (LOCK_PREFIX, __arch, mem)
-
-#define __arch_decrement_cprefix \
- "cmpl $0, %%" SEG_REG ":%P2\n\tje 0f\n\tlock\n0:\t"
+#define atomic_decrement(mem) \
+ __single_op (LOCK_PREFIX, (mem), dec)
-#define catomic_decrement(mem) \
- __arch_decrement_body (__arch_decrement_cprefix, __arch_c, mem)
+#define catomic_decrement(mem) \
+ ({ \
+ if (SINGLE_THREAD_P) \
+ __single_op ("", (mem), dec); \
+ else \
+ atomic_decrement (mem); \
+ })
#define atomic_decrement_and_test(mem) \
@@ -463,73 +293,31 @@
: "=q" (__result), "=m" (*mem) \
: "m" (*mem), "ir" (bit)); \
else \
- __atomic_link_error (); \
+ __atomic_link_error (); \
__result; })
-#define __arch_and_body(lock, mem, mask) \
- do { \
- if (sizeof (*mem) == 1) \
- __asm __volatile (lock "andb %b1, %0" \
- : "=m" (*mem) \
- : IBR_CONSTRAINT (mask), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (sizeof (*mem) == 2) \
- __asm __volatile (lock "andw %w1, %0" \
- : "=m" (*mem) \
- : "ir" (mask), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (sizeof (*mem) == 4) \
- __asm __volatile (lock "andl %1, %0" \
- : "=m" (*mem) \
- : "ir" (mask), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (__HAVE_64B_ATOMICS) \
- __asm __volatile (lock "andq %q1, %0" \
- : "=m" (*mem) \
- : "ir" (mask), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else \
- __atomic_link_error (); \
- } while (0)
-
-#define __arch_cprefix \
- "cmpl $0, %%" SEG_REG ":%P3\n\tje 0f\n\tlock\n0:\t"
-
-#define atomic_and(mem, mask) __arch_and_body (LOCK_PREFIX, mem, mask)
-
-#define catomic_and(mem, mask) __arch_and_body (__arch_cprefix, mem, mask)
+#define atomic_and(mem, mask) \
+ __xchg_op (LOCK_PREFIX, (mem), (mask), and)
+#define catomic_and(mem, mask) \
+ ({ \
+ if (SINGLE_THREAD_P) \
+ __xchg_op ("", (mem), (mask), and); \
+ else \
+ atomic_and (mem, mask); \
+ })
-#define __arch_or_body(lock, mem, mask) \
- do { \
- if (sizeof (*mem) == 1) \
- __asm __volatile (lock "orb %b1, %0" \
- : "=m" (*mem) \
- : IBR_CONSTRAINT (mask), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (sizeof (*mem) == 2) \
- __asm __volatile (lock "orw %w1, %0" \
- : "=m" (*mem) \
- : "ir" (mask), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (sizeof (*mem) == 4) \
- __asm __volatile (lock "orl %1, %0" \
- : "=m" (*mem) \
- : "ir" (mask), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else if (__HAVE_64B_ATOMICS) \
- __asm __volatile (lock "orq %q1, %0" \
- : "=m" (*mem) \
- : "ir" (mask), "m" (*mem), \
- "i" (offsetof (tcbhead_t, multiple_threads))); \
- else \
- __atomic_link_error (); \
- } while (0)
-
-#define atomic_or(mem, mask) __arch_or_body (LOCK_PREFIX, mem, mask)
+#define atomic_or(mem, mask) \
+ __xchg_op (LOCK_PREFIX, (mem), (mask), or)
-#define catomic_or(mem, mask) __arch_or_body (__arch_cprefix, mem, mask)
+#define catomic_or(mem, mask) \
+ ({ \
+ if (SINGLE_THREAD_P) \
+ __xchg_op ("", (mem), (mask), or); \
+ else \
+ atomic_or (mem, mask); \
+ })
/* We don't use mfence because it is supposedly slower due to having to
provide stronger guarantees (e.g., regarding self-modifying code). */
diff --git a/sysdeps/x86_64/nptl/tcb-offsets.sym b/sysdeps/x86_64/nptl/tcb-offsets.sym
index 2bbd563a6c..8ec55a7ea8 100644
--- a/sysdeps/x86_64/nptl/tcb-offsets.sym
+++ b/sysdeps/x86_64/nptl/tcb-offsets.sym
@@ -9,7 +9,6 @@ CLEANUP_JMP_BUF offsetof (struct pthread, cleanup_jmp_buf)
CLEANUP offsetof (struct pthread, cleanup)
CLEANUP_PREV offsetof (struct _pthread_cleanup_buffer, __prev)
MUTEX_FUTEX offsetof (pthread_mutex_t, __data.__lock)
-MULTIPLE_THREADS_OFFSET offsetof (tcbhead_t, multiple_threads)
POINTER_GUARD offsetof (tcbhead_t, pointer_guard)
FEATURE_1_OFFSET offsetof (tcbhead_t, feature_1)
SSP_BASE_OFFSET offsetof (tcbhead_t, ssp_base)
diff --git a/sysdeps/x86_64/nptl/tls.h b/sysdeps/x86_64/nptl/tls.h
index 75f8020975..7967df571f 100644
--- a/sysdeps/x86_64/nptl/tls.h
+++ b/sysdeps/x86_64/nptl/tls.h
@@ -45,7 +45,7 @@ typedef struct
thread descriptor used by libpthread. */
dtv_t *dtv;
void *self; /* Pointer to the thread descriptor. */
- int multiple_threads;
+ int unused_multiple_threads;
int gscope_flag;
uintptr_t sysinfo;
uintptr_t stack_guard;
--
2.34.1
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v3 4/4] Remove single-thread.h
2022-06-21 20:32 [PATCH v3 0/4] Simplify internal single-threaded usage Adhemerval Zanella
` (2 preceding siblings ...)
2022-06-21 20:32 ` [PATCH v3 3/4] Remove usage of TLS_MULTIPLE_THREADS_IN_TCB Adhemerval Zanella
@ 2022-06-21 20:32 ` Adhemerval Zanella
2022-07-05 11:43 ` Wilco Dijkstra
3 siblings, 1 reply; 12+ messages in thread
From: Adhemerval Zanella @ 2022-06-21 20:32 UTC (permalink / raw)
To: libc-alpha, Wilco Dijkstra, Fangrui Song
And move SINGLE_THREAD_P macro to sys/single_threaded.h.
---
include/sys/single_threaded.h | 13 ++++++--
sysdeps/generic/single-thread.h | 25 ----------------
sysdeps/mach/hurd/sysdep-cancel.h | 5 ----
sysdeps/unix/sysdep.h | 2 +-
.../unix/sysv/linux/aarch64/single-thread.h | 2 --
sysdeps/unix/sysv/linux/arc/single-thread.h | 2 --
sysdeps/unix/sysv/linux/arm/single-thread.h | 2 --
sysdeps/unix/sysv/linux/hppa/single-thread.h | 2 --
.../sysv/linux/microblaze/single-thread.h | 2 --
sysdeps/unix/sysv/linux/s390/single-thread.h | 2 --
sysdeps/unix/sysv/linux/single-thread.h | 30 -------------------
.../unix/sysv/linux/x86_64/single-thread.h | 2 --
12 files changed, 11 insertions(+), 78 deletions(-)
delete mode 100644 sysdeps/generic/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/aarch64/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/arc/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/arm/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/hppa/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/microblaze/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/s390/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/x86_64/single-thread.h
diff --git a/include/sys/single_threaded.h b/include/sys/single_threaded.h
index 2015742be0..f42e40547e 100644
--- a/include/sys/single_threaded.h
+++ b/include/sys/single_threaded.h
@@ -1,6 +1,7 @@
-#include <misc/sys/single_threaded.h>
+#ifndef __ASSEMBLER__
+# include <misc/sys/single_threaded.h>
-#ifndef _ISOMAC
+# ifndef _ISOMAC
libc_hidden_proto_alias (__libc_single_threaded,
__libc_single_threaded_internal);
@@ -9,4 +10,10 @@ libc_hidden_proto_alias (__libc_single_threaded,
# define __libc_single_threaded_internal __libc_single_threaded
#endif
-#endif
+# define SINGLE_THREAD_P (__libc_single_threaded_internal != 0)
+
+# define RTLD_SINGLE_THREAD_P SINGLE_THREAD_P
+
+# endif
+
+#endif /* __ASSEMBLER__ */
diff --git a/sysdeps/generic/single-thread.h b/sysdeps/generic/single-thread.h
deleted file mode 100644
index 7f8222b38a..0000000000
--- a/sysdeps/generic/single-thread.h
+++ /dev/null
@@ -1,25 +0,0 @@
-/* Single thread optimization, generic version.
- Copyright (C) 2019-2022 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#ifndef _SINGLE_THREAD_H
-#define _SINGLE_THREAD_H
-
-#define SINGLE_THREAD_P (0)
-#define RTLD_SINGLE_THREAD_P (0)
-
-#endif /* _SINGLE_THREAD_H */
diff --git a/sysdeps/mach/hurd/sysdep-cancel.h b/sysdeps/mach/hurd/sysdep-cancel.h
index 669c17151a..9311367ab9 100644
--- a/sysdeps/mach/hurd/sysdep-cancel.h
+++ b/sysdeps/mach/hurd/sysdep-cancel.h
@@ -6,11 +6,6 @@ void __pthread_disable_asynccancel (int oldtype);
#pragma weak __pthread_enable_asynccancel
#pragma weak __pthread_disable_asynccancel
-/* Always multi-thread (since there's at least the sig handler), but no
- handling enabled. */
-#define SINGLE_THREAD_P (0)
-#define RTLD_SINGLE_THREAD_P (0)
-
#define LIBC_CANCEL_ASYNC() ({ \
int __cancel_oldtype = 0; \
if (__pthread_enable_asynccancel) \
diff --git a/sysdeps/unix/sysdep.h b/sysdeps/unix/sysdep.h
index a1d9df4c73..a8abecb92b 100644
--- a/sysdeps/unix/sysdep.h
+++ b/sysdeps/unix/sysdep.h
@@ -16,7 +16,7 @@
<https://www.gnu.org/licenses/>. */
#include <sysdeps/generic/sysdep.h>
-#include <single-thread.h>
+#include <sys/single_threaded.h>
#include <sys/syscall.h>
#define HAVE_SYSCALLS
diff --git a/sysdeps/unix/sysv/linux/aarch64/single-thread.h b/sysdeps/unix/sysv/linux/aarch64/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/aarch64/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/arc/single-thread.h b/sysdeps/unix/sysv/linux/arc/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/arc/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/arm/single-thread.h b/sysdeps/unix/sysv/linux/arm/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/arm/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/hppa/single-thread.h b/sysdeps/unix/sysv/linux/hppa/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/hppa/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/microblaze/single-thread.h b/sysdeps/unix/sysv/linux/microblaze/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/microblaze/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/s390/single-thread.h b/sysdeps/unix/sysv/linux/s390/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/s390/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/single-thread.h b/sysdeps/unix/sysv/linux/single-thread.h
deleted file mode 100644
index 2099848cf3..0000000000
--- a/sysdeps/unix/sysv/linux/single-thread.h
+++ /dev/null
@@ -1,30 +0,0 @@
-/* Single thread optimization, Linux version.
- Copyright (C) 2019-2022 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#ifndef _SINGLE_THREAD_H
-#define _SINGLE_THREAD_H
-
-#ifndef __ASSEMBLER__
-# include <sys/single_threaded.h>
-#endif
-
-#define SINGLE_THREAD_P (__libc_single_threaded_internal != 0)
-
-#define RTLD_SINGLE_THREAD_P SINGLE_THREAD_P
-
-#endif /* _SINGLE_THREAD_H */
diff --git a/sysdeps/unix/sysv/linux/x86_64/single-thread.h b/sysdeps/unix/sysv/linux/x86_64/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/x86_64/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
--
2.34.1
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 2/4] Replace __libc_multiple_threads with __libc_single_threaded
2022-06-21 20:32 ` [PATCH v3 2/4] Replace __libc_multiple_threads with __libc_single_threaded Adhemerval Zanella
@ 2022-06-22 11:04 ` Yann Droneaud
2022-06-22 12:24 ` Adhemerval Zanella
2022-07-05 11:34 ` Wilco Dijkstra
1 sibling, 1 reply; 12+ messages in thread
From: Yann Droneaud @ 2022-06-22 11:04 UTC (permalink / raw)
To: Adhemerval Zanella, libc-alpha, Wilco Dijkstra, Fangrui Song
Hi,
Le 21/06/2022 à 22:32, Adhemerval Zanella via Libc-alpha a écrit :
> And also fixes the SINGLE_THREAD_P macro for SINGLE_THREAD_BY_GLOBAL,
> since header inclusion single-thread.h is in the wrong order, the define
> needs to come before including sysdeps/unix/sysdep.h. The macro
> is now moved to a per-arch single-threade.h header.
>
> The SINGLE_THREAD_P is used on some more places.
>
> Checked on aarch64-linux-gnu and x86_64-linux-gnu.
> ---
> nptl/Makefile | 1 -
> nptl/allocatestack.c | 6 ----
> nptl/libc_multiple_threads.c | 28 -------------------
> nptl/pthread_cancel.c | 2 +-
> posix/fork.c | 2 +-
> sysdeps/nptl/setxid.h | 2 +-
> .../unix/sysv/linux/aarch64/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/aarch64/sysdep.h | 2 --
> sysdeps/unix/sysv/linux/alpha/sysdep.h | 2 --
> sysdeps/unix/sysv/linux/arc/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/arc/sysdep.h | 2 --
> sysdeps/unix/sysv/linux/arm/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/arm/sysdep.h | 2 --
> sysdeps/unix/sysv/linux/hppa/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/hppa/sysdep.h | 2 --
> .../sysv/linux/microblaze/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/microblaze/sysdep.h | 2 --
> sysdeps/unix/sysv/linux/s390/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/s390/sysdep.h | 3 --
> sysdeps/unix/sysv/linux/single-thread.h | 11 ++++----
> .../unix/sysv/linux/x86_64/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/x86_64/sysdep.h | 2 --
> 22 files changed, 22 insertions(+), 61 deletions(-)
> delete mode 100644 nptl/libc_multiple_threads.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/single-thread.h
> create mode 100644 sysdeps/unix/sysv/linux/arc/single-thread.h
> create mode 100644 sysdeps/unix/sysv/linux/arm/single-thread.h
> create mode 100644 sysdeps/unix/sysv/linux/hppa/single-thread.h
> create mode 100644 sysdeps/unix/sysv/linux/microblaze/single-thread.h
> create mode 100644 sysdeps/unix/sysv/linux/s390/single-thread.h
> create mode 100644 sysdeps/unix/sysv/linux/x86_64/single-thread.h
>
> diff --git a/nptl/Makefile b/nptl/Makefile
> index b585663974..3d2ce8af8a 100644
> --- a/nptl/Makefile
> +++ b/nptl/Makefile
> @@ -50,7 +50,6 @@ routines = \
> events \
> futex-internal \
> libc-cleanup \
> - libc_multiple_threads \
> lowlevellock \
> nptl-stack \
> nptl_deallocate_tsd \
> diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c
> index 01a282f3f6..98f5f6dd85 100644
> --- a/nptl/allocatestack.c
> +++ b/nptl/allocatestack.c
> @@ -292,9 +292,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
>
> /* This is at least the second thread. */
> pd->header.multiple_threads = 1;
> -#ifndef TLS_MULTIPLE_THREADS_IN_TCB
> - __libc_multiple_threads = 1;
> -#endif
>
> #ifdef NEED_DL_SYSINFO
> SETUP_THREAD_SYSINFO (pd);
> @@ -413,9 +410,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
>
> /* This is at least the second thread. */
> pd->header.multiple_threads = 1;
> -#ifndef TLS_MULTIPLE_THREADS_IN_TCB
> - __libc_multiple_threads = 1;
> -#endif
>
> #ifdef NEED_DL_SYSINFO
> SETUP_THREAD_SYSINFO (pd);
> diff --git a/nptl/libc_multiple_threads.c b/nptl/libc_multiple_threads.c
> deleted file mode 100644
> index 0c2dc33d0d..0000000000
> --- a/nptl/libc_multiple_threads.c
> +++ /dev/null
> @@ -1,28 +0,0 @@
> -/* Copyright (C) 2002-2022 Free Software Foundation, Inc.
> - This file is part of the GNU C Library.
> -
> - The GNU C Library is free software; you can redistribute it and/or
> - modify it under the terms of the GNU Lesser General Public
> - License as published by the Free Software Foundation; either
> - version 2.1 of the License, or (at your option) any later version.
> -
> - The GNU C Library is distributed in the hope that it will be useful,
> - but WITHOUT ANY WARRANTY; without even the implied warranty of
> - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> - Lesser General Public License for more details.
> -
> - You should have received a copy of the GNU Lesser General Public
> - License along with the GNU C Library; if not, see
> - <https://www.gnu.org/licenses/>. */
> -
> -#include <pthreadP.h>
> -
> -#if IS_IN (libc)
> -# ifndef TLS_MULTIPLE_THREADS_IN_TCB
> -/* Variable set to a nonzero value either if more than one thread runs or ran,
> - or if a single-threaded process is trying to cancel itself. See
> - nptl/descr.h for more context on the single-threaded process case. */
> -int __libc_multiple_threads;
> -libc_hidden_data_def (__libc_multiple_threads)
> -# endif
> -#endif
> diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c
> index e67b2df5cc..459317df49 100644
> --- a/nptl/pthread_cancel.c
> +++ b/nptl/pthread_cancel.c
> @@ -161,7 +161,7 @@ __pthread_cancel (pthread_t th)
> points get executed. */
> THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
> #ifndef TLS_MULTIPLE_THREADS_IN_TCB
> - __libc_multiple_threads = 1;
> + __libc_single_threaded_internal = 0;
> #endif
> }
> while (!atomic_compare_exchange_weak_acquire (&pd->cancelhandling, &oldval,
> diff --git a/posix/fork.c b/posix/fork.c
> index 987916a175..cee5ae83c8 100644
> --- a/posix/fork.c
> +++ b/posix/fork.c
> @@ -45,7 +45,7 @@ __libc_fork (void)
> requirement for fork (Austin Group tracker issue #62) this is
> best effort to make is async-signal-safe at least for single-thread
> case. */
> - bool multiple_threads = __libc_single_threaded_internal == 0;
> + bool multiple_threads = !SINGLE_THREAD_P;
> uint64_t lastrun;
>
> lastrun = __run_prefork_handlers (multiple_threads);
> diff --git a/sysdeps/nptl/setxid.h b/sysdeps/nptl/setxid.h
> index b87cad7b18..3a412179ac 100644
> --- a/sysdeps/nptl/setxid.h
> +++ b/sysdeps/nptl/setxid.h
> @@ -29,7 +29,7 @@
> #define INLINE_SETXID_SYSCALL(name, nr, args...) \
> ({ \
> int __result; \
> - if (!__libc_single_threaded_internal) \
> + if (!SINGLE_THREAD_P) \
> { \
> struct xid_command __cmd; \
> __cmd.syscall_no = __NR_##name; \
> diff --git a/sysdeps/unix/sysv/linux/aarch64/single-thread.h b/sysdeps/unix/sysv/linux/aarch64/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/aarch64/sysdep.h b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
> index 3b230dccf1..f1853e012f 100644
> --- a/sysdeps/unix/sysv/linux/aarch64/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
> @@ -164,8 +164,6 @@
> # define HAVE_CLOCK_GETTIME64_VSYSCALL "__kernel_clock_gettime"
> # define HAVE_GETTIMEOFDAY_VSYSCALL "__kernel_gettimeofday"
>
> -# define SINGLE_THREAD_BY_GLOBAL 1
> -
> # undef INTERNAL_SYSCALL_RAW
> # define INTERNAL_SYSCALL_RAW(name, nr, args...) \
> ({ long _sys_result; \
> diff --git a/sysdeps/unix/sysv/linux/alpha/sysdep.h b/sysdeps/unix/sysv/linux/alpha/sysdep.h
> index 3051a744b4..77ec2b5400 100644
> --- a/sysdeps/unix/sysv/linux/alpha/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/alpha/sysdep.h
> @@ -32,8 +32,6 @@
> #undef SYS_ify
> #define SYS_ify(syscall_name) __NR_##syscall_name
>
> -#define SINGLE_THREAD_BY_GLOBAL 1
> -
> #ifdef __ASSEMBLER__
> #include <asm/pal.h>
> #include <alpha/regdef.h>
> diff --git a/sysdeps/unix/sysv/linux/arc/single-thread.h b/sysdeps/unix/sysv/linux/arc/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/arc/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/arc/sysdep.h b/sysdeps/unix/sysv/linux/arc/sysdep.h
> index 29b0e0161c..d0c1a78381 100644
> --- a/sysdeps/unix/sysv/linux/arc/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/arc/sysdep.h
> @@ -132,8 +132,6 @@ L (call_syscall_err): ASM_LINE_SEP \
>
> #else /* !__ASSEMBLER__ */
>
> -# define SINGLE_THREAD_BY_GLOBAL 1
> -
> # if IS_IN (libc)
> extern long int __syscall_error (long int);
> hidden_proto (__syscall_error)
> diff --git a/sysdeps/unix/sysv/linux/arm/single-thread.h b/sysdeps/unix/sysv/linux/arm/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/arm/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/arm/sysdep.h b/sysdeps/unix/sysv/linux/arm/sysdep.h
> index 7bdd218063..1f270b961e 100644
> --- a/sysdeps/unix/sysv/linux/arm/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/arm/sysdep.h
> @@ -408,8 +408,6 @@ __local_syscall_error: \
> #define INTERNAL_SYSCALL_NCS(number, nr, args...) \
> INTERNAL_SYSCALL_RAW (number, nr, args)
>
> -#define SINGLE_THREAD_BY_GLOBAL 1
> -
> #endif /* __ASSEMBLER__ */
>
> #endif /* linux/arm/sysdep.h */
> diff --git a/sysdeps/unix/sysv/linux/hppa/single-thread.h b/sysdeps/unix/sysv/linux/hppa/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/hppa/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/hppa/sysdep.h b/sysdeps/unix/sysv/linux/hppa/sysdep.h
> index 42f7705852..2f339a4bd6 100644
> --- a/sysdeps/unix/sysv/linux/hppa/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/hppa/sysdep.h
> @@ -474,6 +474,4 @@ L(pre_end): ASM_LINE_SEP \
> #define PTR_MANGLE(var) (void) (var)
> #define PTR_DEMANGLE(var) (void) (var)
>
> -#define SINGLE_THREAD_BY_GLOBAL 1
> -
> #endif /* _LINUX_HPPA_SYSDEP_H */
> diff --git a/sysdeps/unix/sysv/linux/microblaze/single-thread.h b/sysdeps/unix/sysv/linux/microblaze/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/microblaze/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/microblaze/sysdep.h b/sysdeps/unix/sysv/linux/microblaze/sysdep.h
> index dfd6312506..fda78f6467 100644
> --- a/sysdeps/unix/sysv/linux/microblaze/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/microblaze/sysdep.h
> @@ -308,8 +308,6 @@ SYSCALL_ERROR_LABEL_DCL: \
> # define PTR_MANGLE(var) (void) (var)
> # define PTR_DEMANGLE(var) (void) (var)
>
> -# define SINGLE_THREAD_BY_GLOBAL 1
> -
> #undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
> #define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
>
> diff --git a/sysdeps/unix/sysv/linux/s390/single-thread.h b/sysdeps/unix/sysv/linux/s390/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/s390/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/s390/sysdep.h b/sysdeps/unix/sysv/linux/s390/sysdep.h
> index 78c7e8c7e2..2d0a26779c 100644
> --- a/sysdeps/unix/sysv/linux/s390/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/s390/sysdep.h
> @@ -93,9 +93,6 @@
> #define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
> #define ASMFMT_6 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6), "d" (gpr7)
>
> -#define SINGLE_THREAD_BY_GLOBAL 1
> -
> -
> #define VDSO_NAME "LINUX_2.6.29"
> #define VDSO_HASH 123718585
>
> diff --git a/sysdeps/unix/sysv/linux/single-thread.h b/sysdeps/unix/sysv/linux/single-thread.h
> index 4529a906d2..30dde4e81a 100644
> --- a/sysdeps/unix/sysv/linux/single-thread.h
> +++ b/sysdeps/unix/sysv/linux/single-thread.h
> @@ -19,6 +19,10 @@
> #ifndef _SINGLE_THREAD_H
> #define _SINGLE_THREAD_H
>
> +#ifndef __ASSEMBLER__
> +# include <sys/single_threaded.h>
> +#endif
> +
> /* The default way to check if the process is single thread is by using the
> pthread_t 'multiple_threads' field. However, for some architectures it is
> faster to either use an extra field on TCB or global variables (the TCB
> @@ -27,16 +31,11 @@
> The ABI might define SINGLE_THREAD_BY_GLOBAL to enable the single thread
> check to use global variables instead of the pthread_t field. */
>
> -#ifndef __ASSEMBLER__
> -extern int __libc_multiple_threads;
> -libc_hidden_proto (__libc_multiple_threads)
> -#endif
> -
> #if !defined SINGLE_THREAD_BY_GLOBAL || IS_IN (rtld)
SINGLE_THREAD_BY_GLOBAL doesn't seem to be defined after this patch, so can it this be updated as:
- #if !defined SINGLE_THREAD_BY_GLOBAL || IS_IN (rtld)
+ #if IS_IN(rtld)
> # define SINGLE_THREAD_P \
> (THREAD_GETMEM (THREAD_SELF, header.multiple_threads) == 0)
> #else
> -# define SINGLE_THREAD_P (__libc_multiple_threads == 0)
> +# define SINGLE_THREAD_P (__libc_single_threaded_internal != 0)
> #endif
>
> #define RTLD_SINGLE_THREAD_P SINGLE_THREAD_P
> diff --git a/sysdeps/unix/sysv/linux/x86_64/single-thread.h b/sysdeps/unix/sysv/linux/x86_64/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/x86_64/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/x86_64/sysdep.h b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
> index e1ce3b62eb..740abefcfd 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
> @@ -379,8 +379,6 @@
>
> # define HAVE_CLONE3_WRAPPER 1
>
> -# define SINGLE_THREAD_BY_GLOBAL 1
> -
> #endif /* __ASSEMBLER__ */
>
>
Regards.
--
Yann Droneaud
OPTEYA
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 2/4] Replace __libc_multiple_threads with __libc_single_threaded
2022-06-22 11:04 ` Yann Droneaud
@ 2022-06-22 12:24 ` Adhemerval Zanella
2022-06-22 13:53 ` Yann Droneaud
0 siblings, 1 reply; 12+ messages in thread
From: Adhemerval Zanella @ 2022-06-22 12:24 UTC (permalink / raw)
To: Yann Droneaud; +Cc: GNU C Library, Wilco Dijkstra, Fangrui Song
> On 22 Jun 2022, at 08:04, Yann Droneaud <ydroneaud@opteya.com> wrote:
>
>> diff --git a/sysdeps/unix/sysv/linux/single-thread.h b/sysdeps/unix/sysv/linux/single-thread.h
>> index 4529a906d2..30dde4e81a 100644
>> --- a/sysdeps/unix/sysv/linux/single-thread.h
>> +++ b/sysdeps/unix/sysv/linux/single-thread.h
>> @@ -19,6 +19,10 @@
>> #ifndef _SINGLE_THREAD_H
>> #define _SINGLE_THREAD_H
>> +#ifndef __ASSEMBLER__
>> +# include <sys/single_threaded.h>
>> +#endif
>> +
>> /* The default way to check if the process is single thread is by using the
>> pthread_t 'multiple_threads' field. However, for some architectures it is
>> faster to either use an extra field on TCB or global variables (the TCB
>> @@ -27,16 +31,11 @@
>> The ABI might define SINGLE_THREAD_BY_GLOBAL to enable the single thread
>> check to use global variables instead of the pthread_t field. */
>> -#ifndef __ASSEMBLER__
>> -extern int __libc_multiple_threads;
>> -libc_hidden_proto (__libc_multiple_threads)
>> -#endif
>> -
>> #if !defined SINGLE_THREAD_BY_GLOBAL || IS_IN (rtld)
>
> SINGLE_THREAD_BY_GLOBAL doesn't seem to be defined after this patch, so can it this be updated as:
It is moved from sysdep.h to each arch-specific single-thread.h header,
so it is really used for this patch.
The third patch refactor the SINGLE_THREAD_P macro to remove the
SINGLE_THREAD_BY_GLOBAL and the forth patch finally remove all its
definition.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 2/4] Replace __libc_multiple_threads with __libc_single_threaded
2022-06-22 12:24 ` Adhemerval Zanella
@ 2022-06-22 13:53 ` Yann Droneaud
0 siblings, 0 replies; 12+ messages in thread
From: Yann Droneaud @ 2022-06-22 13:53 UTC (permalink / raw)
To: Adhemerval Zanella; +Cc: GNU C Library, Wilco Dijkstra
Hi,
Le 22/06/2022 à 14:24, Adhemerval Zanella via Libc-alpha a écrit :
>> On 22 Jun 2022, at 08:04, Yann Droneaud <ydroneaud@opteya.com> wrote:
>>
>>> diff --git a/sysdeps/unix/sysv/linux/single-thread.h b/sysdeps/unix/sysv/linux/single-thread.h
>>> index 4529a906d2..30dde4e81a 100644
>>> --- a/sysdeps/unix/sysv/linux/single-thread.h
>>> +++ b/sysdeps/unix/sysv/linux/single-thread.h
>>> @@ -19,6 +19,10 @@
>>> #ifndef _SINGLE_THREAD_H
>>> #define _SINGLE_THREAD_H
>>> +#ifndef __ASSEMBLER__
>>> +# include <sys/single_threaded.h>
>>> +#endif
>>> +
>>> /* The default way to check if the process is single thread is by using the
>>> pthread_t 'multiple_threads' field. However, for some architectures it is
>>> faster to either use an extra field on TCB or global variables (the TCB
>>> @@ -27,16 +31,11 @@
>>> The ABI might define SINGLE_THREAD_BY_GLOBAL to enable the single thread
>>> check to use global variables instead of the pthread_t field. */
>>> -#ifndef __ASSEMBLER__
>>> -extern int __libc_multiple_threads;
>>> -libc_hidden_proto (__libc_multiple_threads)
>>> -#endif
>>> -
>>> #if !defined SINGLE_THREAD_BY_GLOBAL || IS_IN (rtld)
>> SINGLE_THREAD_BY_GLOBAL doesn't seem to be defined after this patch, so can it this be updated as:
> It is moved from sysdep.h to each arch-specific single-thread.h header,
> so it is really used for this patch.
My bad, sorry.
Regards.
--
Yann Droneaud
OPTEYA
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 1/4] misc: Optimize internal usage of __libc_single_threaded
2022-06-21 20:32 ` [PATCH v3 1/4] misc: Optimize internal usage of __libc_single_threaded Adhemerval Zanella
@ 2022-06-23 4:15 ` Fangrui Song
2022-06-23 14:05 ` Adhemerval Zanella
0 siblings, 1 reply; 12+ messages in thread
From: Fangrui Song @ 2022-06-23 4:15 UTC (permalink / raw)
To: Adhemerval Zanella; +Cc: libc-alpha, Wilco Dijkstra
On 2022-06-21, Adhemerval Zanella wrote:
>By adding an internal alias to avoid the GOT indirection.
>On some architecture, __libc_single_thread may be accessed through
>copy relocations and thus it requires to update also the copies
>default copy.
>
>This is done by adding a new internal macro,
>libc_hidden_data_{proto,def}, which has an addition argument that
>specifies the alias name (instead of default __GI_ one).
>
>Checked on x86_64-linux-gnu and i686-linux-gnu.
>---
> elf/libc_early_init.c | 2 +-
> include/libc-symbols.h | 22 ++++++++++++++++++++++
> include/sys/single_threaded.h | 11 +++++++++++
> misc/single_threaded.c | 2 ++
> nptl/pthread_create.c | 5 ++++-
> posix/fork.c | 2 +-
> sysdeps/nptl/setxid.h | 2 +-
> 7 files changed, 42 insertions(+), 4 deletions(-)
>
>diff --git a/elf/libc_early_init.c b/elf/libc_early_init.c
>index 3c4a19cf6b..affc46fefc 100644
>--- a/elf/libc_early_init.c
>+++ b/elf/libc_early_init.c
>@@ -38,7 +38,7 @@ __libc_early_init (_Bool initial)
> __libc_single_threaded = initial;
>
> #ifdef SHARED
>- __libc_initial = initial;
>+ __libc_single_threaded_internal = __libc_initial = initial;
> #endif
>
> __pthread_early_init ();
>diff --git a/include/libc-symbols.h b/include/libc-symbols.h
>index 4bb3d8c7ba..4fde839471 100644
>--- a/include/libc-symbols.h
>+++ b/include/libc-symbols.h
>@@ -534,11 +534,15 @@ for linking")
> __attribute__ ((visibility ("hidden"), ##attrs))
> # define hidden_proto(name, attrs...) \
> __hidden_proto (name, , __GI_##name, ##attrs)
>+# define hidden_proto_alias(name, alias, attrs...) \
>+ __hidden_proto_alias (name, , alias, ##attrs)
> # define hidden_tls_proto(name, attrs...) \
> __hidden_proto (name, __thread, __GI_##name, ##attrs)
> # define __hidden_proto(name, thread, internal, attrs...) \
> extern thread __typeof (name) name __asm__ (__hidden_asmname (#internal)) \
> __hidden_proto_hiddenattr (attrs);
>+# define __hidden_proto_alias(name, thread, internal, attrs...) \
>+ extern thread __typeof (name) internal __hidden_proto_hiddenattr (attrs);
> # define __hidden_asmname(name) \
> __hidden_asmname1 (__USER_LABEL_PREFIX__, name)
> # define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name)
>@@ -554,7 +558,10 @@ for linking")
> # define hidden_ver(local, name) __hidden_ver1(local, __GI_##name, name);
> # define hidden_data_ver(local, name) hidden_ver(local, name)
> # define hidden_def(name) __hidden_ver1(__GI_##name, name, name);
>+# define hidden_def_alias(name, internal) \
>+ strong_alias (name, internal)
> # define hidden_data_def(name) hidden_def(name)
>+# define hidden_data_def_alias(name, alias) hidden_def_alias(name, alias)
> # define hidden_tls_def(name) \
> __hidden_ver2 (__thread, __GI_##name, name, name);
> # define hidden_weak(name) \
>@@ -581,9 +588,11 @@ for linking")
> hidden_proto doesn't make sense for assembly but the equivalent
> is to call via the HIDDEN_JUMPTARGET macro instead of JUMPTARGET. */
> # define hidden_def(name) strong_alias (name, __GI_##name)
>+# define hidden_def_alias(name, alias) strong_alias (name, alias)
> # define hidden_weak(name) hidden_def (name)
> # define hidden_ver(local, name) strong_alias (local, __GI_##name)
> # define hidden_data_def(name) strong_data_alias (name, __GI_##name)
>+# define hidden_data_def_alias(name, alias) strong_data_alias (name, alias)
> # define hidden_tls_def(name) hidden_data_def (name)
> # define hidden_data_weak(name) hidden_data_def (name)
> # define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name)
>@@ -598,12 +607,17 @@ for linking")
> __attribute__ ((visibility ("hidden"), ##attrs))
> # define hidden_proto(name, attrs...) \
> __hidden_proto (name, , name, ##attrs)
>+# define hidden_proto_alias(name, alias, attrs...) \
>+ __hidden_proto_alias (name, , alias, ##attrs)
> # define hidden_tls_proto(name, attrs...) \
> __hidden_proto (name, __thread, name, ##attrs)
> # define __hidden_proto(name, thread, internal, attrs...) \
> extern thread __typeof (name) name __hidden_proto_hiddenattr (attrs);
>+# define __hidden_proto_alias(name, thread, internal, attrs...) \
>+ extern thread __typeof (name) internal __hidden_proto_hiddenattr (attrs);
> # else
> # define hidden_proto(name, attrs...)
>+# define hidden_proto_alias(name, alias, attrs...)
> # define hidden_tls_proto(name, attrs...)
> # endif
> # else
>@@ -611,9 +625,11 @@ for linking")
> # endif /* Not __ASSEMBLER__ */
> # define hidden_weak(name)
> # define hidden_def(name)
>+# define hidden_def_alias(name, alias)
> # define hidden_ver(local, name)
> # define hidden_data_weak(name)
> # define hidden_data_def(name)
>+# define hidden_data_def_alias(name, alias)
> # define hidden_tls_def(name)
> # define hidden_data_ver(local, name)
> # define hidden_nolink(name, lib, version)
>@@ -621,22 +637,28 @@ for linking")
>
> #if IS_IN (libc)
> # define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
>+# define libc_hidden_proto_alias(name, alias, attrs...) \
>+ hidden_proto_alias (name, alias, ##attrs)
> # define libc_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
> # define libc_hidden_def(name) hidden_def (name)
>+# define libc_hidden_def_alias(name, alias) hidden_def_alias (name, alias)
> # define libc_hidden_weak(name) hidden_weak (name)
> # define libc_hidden_nolink_sunrpc(name, version) hidden_nolink (name, libc, version)
> # define libc_hidden_ver(local, name) hidden_ver (local, name)
> # define libc_hidden_data_def(name) hidden_data_def (name)
>+# define libc_hidden_data_def_alias(name, alias) hidden_data_def_alias (name, alias)
> # define libc_hidden_tls_def(name) hidden_tls_def (name)
> # define libc_hidden_data_weak(name) hidden_data_weak (name)
> # define libc_hidden_data_ver(local, name) hidden_data_ver (local, name)
> #else
> # define libc_hidden_proto(name, attrs...)
>+# define libc_hidden_proto_alias(name, alias, attrs...)
> # define libc_hidden_tls_proto(name, attrs...)
> # define libc_hidden_def(name)
> # define libc_hidden_weak(name)
> # define libc_hidden_ver(local, name)
> # define libc_hidden_data_def(name)
>+# define libc_hidden_data_def_alias(name, alias)
> # define libc_hidden_tls_def(name)
> # define libc_hidden_data_weak(name)
> # define libc_hidden_data_ver(local, name)
include/libc-symbols.h is very difficult to read.
I can only use the preprocessed output to understand that this patch
works as intended.
I wish that we can simplify the file a bit :-)
>diff --git a/include/sys/single_threaded.h b/include/sys/single_threaded.h
>index 18f6972482..2015742be0 100644
>--- a/include/sys/single_threaded.h
>+++ b/include/sys/single_threaded.h
>@@ -1 +1,12 @@
> #include <misc/sys/single_threaded.h>
>+
>+#ifndef _ISOMAC
>+
>+libc_hidden_proto_alias (__libc_single_threaded,
>+ __libc_single_threaded_internal);
>+
>+#if !defined SHARED || !IS_IN(libc)
>+# define __libc_single_threaded_internal __libc_single_threaded
>+#endif
>+
>+#endif
Does this file need a header guard now?
>diff --git a/misc/single_threaded.c b/misc/single_threaded.c
>index 96ada9137b..9b0746a69c 100644
>--- a/misc/single_threaded.c
>+++ b/misc/single_threaded.c
>@@ -25,3 +25,5 @@ char __libc_single_threaded;
> #else
> char __libc_single_threaded = 1;
> #endif
>+libc_hidden_data_def_alias (__libc_single_threaded,
>+ __libc_single_threaded_internal)
>diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
>index e7a099acb7..5b98e053d6 100644
>--- a/nptl/pthread_create.c
>+++ b/nptl/pthread_create.c
>@@ -624,9 +624,12 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
>
> /* Avoid a data race in the multi-threaded case, and call the
> deferred initialization only once. */
>- if (__libc_single_threaded)
>+ if (__libc_single_threaded_internal)
> {
> late_init ();
>+ __libc_single_threaded_internal = 0;
>+ /* __libc_single_threaded can be accessed through copy relocations, so
>+ it requires to update the external copy. */
> __libc_single_threaded = 0;
> }
LGTM. I verify that __libc_single_threaded has a GLOB_DAT.
Reviewed-by: Fangrui Song <maskray@google.com>
>diff --git a/posix/fork.c b/posix/fork.c
>index e1be3422ea..987916a175 100644
>--- a/posix/fork.c
>+++ b/posix/fork.c
>@@ -45,7 +45,7 @@ __libc_fork (void)
> requirement for fork (Austin Group tracker issue #62) this is
> best effort to make is async-signal-safe at least for single-thread
> case. */
>- bool multiple_threads = __libc_single_threaded == 0;
>+ bool multiple_threads = __libc_single_threaded_internal == 0;
> uint64_t lastrun;
>
> lastrun = __run_prefork_handlers (multiple_threads);
>diff --git a/sysdeps/nptl/setxid.h b/sysdeps/nptl/setxid.h
>index b821d6bc07..b87cad7b18 100644
>--- a/sysdeps/nptl/setxid.h
>+++ b/sysdeps/nptl/setxid.h
>@@ -29,7 +29,7 @@
> #define INLINE_SETXID_SYSCALL(name, nr, args...) \
> ({ \
> int __result; \
>- if (!__libc_single_threaded) \
>+ if (!__libc_single_threaded_internal) \
> { \
> struct xid_command __cmd; \
> __cmd.syscall_no = __NR_##name; \
>--
>2.34.1
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 1/4] misc: Optimize internal usage of __libc_single_threaded
2022-06-23 4:15 ` Fangrui Song
@ 2022-06-23 14:05 ` Adhemerval Zanella
0 siblings, 0 replies; 12+ messages in thread
From: Adhemerval Zanella @ 2022-06-23 14:05 UTC (permalink / raw)
To: Fangrui Song; +Cc: GNU C Library, Wilco Dijkstra
> On 23 Jun 2022, at 01:15, Fangrui Song <maskray@google.com> wrote:
>
> On 2022-06-21, Adhemerval Zanella wrote:
>> By adding an internal alias to avoid the GOT indirection.
>> On some architecture, __libc_single_thread may be accessed through
>> copy relocations and thus it requires to update also the copies
>> default copy.
>>
>> This is done by adding a new internal macro,
>> libc_hidden_data_{proto,def}, which has an addition argument that
>> specifies the alias name (instead of default __GI_ one).
>>
>> Checked on x86_64-linux-gnu and i686-linux-gnu.
>> ---
>> elf/libc_early_init.c | 2 +-
>> include/libc-symbols.h | 22 ++++++++++++++++++++++
>> include/sys/single_threaded.h | 11 +++++++++++
>> misc/single_threaded.c | 2 ++
>> nptl/pthread_create.c | 5 ++++-
>> posix/fork.c | 2 +-
>> sysdeps/nptl/setxid.h | 2 +-
>> 7 files changed, 42 insertions(+), 4 deletions(-)
>>
>> diff --git a/elf/libc_early_init.c b/elf/libc_early_init.c
>> index 3c4a19cf6b..affc46fefc 100644
>> --- a/elf/libc_early_init.c
>> +++ b/elf/libc_early_init.c
>> @@ -38,7 +38,7 @@ __libc_early_init (_Bool initial)
>> __libc_single_threaded = initial;
>>
>> #ifdef SHARED
>> - __libc_initial = initial;
>> + __libc_single_threaded_internal = __libc_initial = initial;
>> #endif
>>
>> __pthread_early_init ();
>> diff --git a/include/libc-symbols.h b/include/libc-symbols.h
>> index 4bb3d8c7ba..4fde839471 100644
>> --- a/include/libc-symbols.h
>> +++ b/include/libc-symbols.h
>> @@ -534,11 +534,15 @@ for linking")
>> __attribute__ ((visibility ("hidden"), ##attrs))
>> # define hidden_proto(name, attrs...) \
>> __hidden_proto (name, , __GI_##name, ##attrs)
>> +# define hidden_proto_alias(name, alias, attrs...) \
>> + __hidden_proto_alias (name, , alias, ##attrs)
>> # define hidden_tls_proto(name, attrs...) \
>> __hidden_proto (name, __thread, __GI_##name, ##attrs)
>> # define __hidden_proto(name, thread, internal, attrs...) \
>> extern thread __typeof (name) name __asm__ (__hidden_asmname (#internal)) \
>> __hidden_proto_hiddenattr (attrs);
>> +# define __hidden_proto_alias(name, thread, internal, attrs...) \
>> + extern thread __typeof (name) internal __hidden_proto_hiddenattr (attrs);
>> # define __hidden_asmname(name) \
>> __hidden_asmname1 (__USER_LABEL_PREFIX__, name)
>> # define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name)
>> @@ -554,7 +558,10 @@ for linking")
>> # define hidden_ver(local, name) __hidden_ver1(local, __GI_##name, name);
>> # define hidden_data_ver(local, name) hidden_ver(local, name)
>> # define hidden_def(name) __hidden_ver1(__GI_##name, name, name);
>> +# define hidden_def_alias(name, internal) \
>> + strong_alias (name, internal)
>> # define hidden_data_def(name) hidden_def(name)
>> +# define hidden_data_def_alias(name, alias) hidden_def_alias(name, alias)
>> # define hidden_tls_def(name) \
>> __hidden_ver2 (__thread, __GI_##name, name, name);
>> # define hidden_weak(name) \
>> @@ -581,9 +588,11 @@ for linking")
>> hidden_proto doesn't make sense for assembly but the equivalent
>> is to call via the HIDDEN_JUMPTARGET macro instead of JUMPTARGET. */
>> # define hidden_def(name) strong_alias (name, __GI_##name)
>> +# define hidden_def_alias(name, alias) strong_alias (name, alias)
>> # define hidden_weak(name) hidden_def (name)
>> # define hidden_ver(local, name) strong_alias (local, __GI_##name)
>> # define hidden_data_def(name) strong_data_alias (name, __GI_##name)
>> +# define hidden_data_def_alias(name, alias) strong_data_alias (name, alias)
>> # define hidden_tls_def(name) hidden_data_def (name)
>> # define hidden_data_weak(name) hidden_data_def (name)
>> # define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name)
>> @@ -598,12 +607,17 @@ for linking")
>> __attribute__ ((visibility ("hidden"), ##attrs))
>> # define hidden_proto(name, attrs...) \
>> __hidden_proto (name, , name, ##attrs)
>> +# define hidden_proto_alias(name, alias, attrs...) \
>> + __hidden_proto_alias (name, , alias, ##attrs)
>> # define hidden_tls_proto(name, attrs...) \
>> __hidden_proto (name, __thread, name, ##attrs)
>> # define __hidden_proto(name, thread, internal, attrs...) \
>> extern thread __typeof (name) name __hidden_proto_hiddenattr (attrs);
>> +# define __hidden_proto_alias(name, thread, internal, attrs...) \
>> + extern thread __typeof (name) internal __hidden_proto_hiddenattr (attrs);
>> # else
>> # define hidden_proto(name, attrs...)
>> +# define hidden_proto_alias(name, alias, attrs...)
>> # define hidden_tls_proto(name, attrs...)
>> # endif
>> # else
>> @@ -611,9 +625,11 @@ for linking")
>> # endif /* Not __ASSEMBLER__ */
>> # define hidden_weak(name)
>> # define hidden_def(name)
>> +# define hidden_def_alias(name, alias)
>> # define hidden_ver(local, name)
>> # define hidden_data_weak(name)
>> # define hidden_data_def(name)
>> +# define hidden_data_def_alias(name, alias)
>> # define hidden_tls_def(name)
>> # define hidden_data_ver(local, name)
>> # define hidden_nolink(name, lib, version)
>> @@ -621,22 +637,28 @@ for linking")
>>
>> #if IS_IN (libc)
>> # define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
>> +# define libc_hidden_proto_alias(name, alias, attrs...) \
>> + hidden_proto_alias (name, alias, ##attrs)
>> # define libc_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
>> # define libc_hidden_def(name) hidden_def (name)
>> +# define libc_hidden_def_alias(name, alias) hidden_def_alias (name, alias)
>> # define libc_hidden_weak(name) hidden_weak (name)
>> # define libc_hidden_nolink_sunrpc(name, version) hidden_nolink (name, libc, version)
>> # define libc_hidden_ver(local, name) hidden_ver (local, name)
>> # define libc_hidden_data_def(name) hidden_data_def (name)
>> +# define libc_hidden_data_def_alias(name, alias) hidden_data_def_alias (name, alias)
>> # define libc_hidden_tls_def(name) hidden_tls_def (name)
>> # define libc_hidden_data_weak(name) hidden_data_weak (name)
>> # define libc_hidden_data_ver(local, name) hidden_data_ver (local, name)
>> #else
>> # define libc_hidden_proto(name, attrs...)
>> +# define libc_hidden_proto_alias(name, alias, attrs...)
>> # define libc_hidden_tls_proto(name, attrs...)
>> # define libc_hidden_def(name)
>> # define libc_hidden_weak(name)
>> # define libc_hidden_ver(local, name)
>> # define libc_hidden_data_def(name)
>> +# define libc_hidden_data_def_alias(name, alias)
>> # define libc_hidden_tls_def(name)
>> # define libc_hidden_data_weak(name)
>> # define libc_hidden_data_ver(local, name)
>
> include/libc-symbols.h is very difficult to read.
> I can only use the preprocessed output to understand that this patch
> works as intended.
>
> I wish that we can simplify the file a bit :-)
The libc-symbols.h requires to define different macros for C and ASM
and it does have some cruft that we might clean up (like some unused
macros and maybe old binutils support).
>
>> diff --git a/include/sys/single_threaded.h b/include/sys/single_threaded.h
>> index 18f6972482..2015742be0 100644
>> --- a/include/sys/single_threaded.h
>> +++ b/include/sys/single_threaded.h
>> @@ -1 +1,12 @@
>> #include <misc/sys/single_threaded.h>
>> +
>> +#ifndef _ISOMAC
>> +
>> +libc_hidden_proto_alias (__libc_single_threaded,
>> + __libc_single_threaded_internal);
>> +
>> +#if !defined SHARED || !IS_IN(libc)
>> +# define __libc_single_threaded_internal __libc_single_threaded
>> +#endif
>> +
>> +#endif
>
> Does this file need a header guard now?
The _ISOMAC is required so we can use the header on tests. And
the SHARED || !IS_IN(libc) is to avoid the optimization on Hurd
(since it still has the pthread library outside libc).
>
>> diff --git a/misc/single_threaded.c b/misc/single_threaded.c
>> index 96ada9137b..9b0746a69c 100644
>> --- a/misc/single_threaded.c
>> +++ b/misc/single_threaded.c
>> @@ -25,3 +25,5 @@ char __libc_single_threaded;
>> #else
>> char __libc_single_threaded = 1;
>> #endif
>> +libc_hidden_data_def_alias (__libc_single_threaded,
>> + __libc_single_threaded_internal)
>> diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
>> index e7a099acb7..5b98e053d6 100644
>> --- a/nptl/pthread_create.c
>> +++ b/nptl/pthread_create.c
>> @@ -624,9 +624,12 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
>>
>> /* Avoid a data race in the multi-threaded case, and call the
>> deferred initialization only once. */
>> - if (__libc_single_threaded)
>> + if (__libc_single_threaded_internal)
>> {
>> late_init ();
>> + __libc_single_threaded_internal = 0;
>> + /* __libc_single_threaded can be accessed through copy relocations, so
>> + it requires to update the external copy. */
>> __libc_single_threaded = 0;
>> }
>
> LGTM. I verify that __libc_single_threaded has a GLOB_DAT.
>
> Reviewed-by: Fangrui Song <maskray@google.com>
Thanks.
>
>> diff --git a/posix/fork.c b/posix/fork.c
>> index e1be3422ea..987916a175 100644
>> --- a/posix/fork.c
>> +++ b/posix/fork.c
>> @@ -45,7 +45,7 @@ __libc_fork (void)
>> requirement for fork (Austin Group tracker issue #62) this is
>> best effort to make is async-signal-safe at least for single-thread
>> case. */
>> - bool multiple_threads = __libc_single_threaded == 0;
>> + bool multiple_threads = __libc_single_threaded_internal == 0;
>> uint64_t lastrun;
>>
>> lastrun = __run_prefork_handlers (multiple_threads);
>> diff --git a/sysdeps/nptl/setxid.h b/sysdeps/nptl/setxid.h
>> index b821d6bc07..b87cad7b18 100644
>> --- a/sysdeps/nptl/setxid.h
>> +++ b/sysdeps/nptl/setxid.h
>> @@ -29,7 +29,7 @@
>> #define INLINE_SETXID_SYSCALL(name, nr, args...) \
>> ({ \
>> int __result; \
>> - if (!__libc_single_threaded) \
>> + if (!__libc_single_threaded_internal) \
>> { \
>> struct xid_command __cmd; \
>> __cmd.syscall_no = __NR_##name; \
>> --
>> 2.34.1
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 2/4] Replace __libc_multiple_threads with __libc_single_threaded
2022-06-21 20:32 ` [PATCH v3 2/4] Replace __libc_multiple_threads with __libc_single_threaded Adhemerval Zanella
2022-06-22 11:04 ` Yann Droneaud
@ 2022-07-05 11:34 ` Wilco Dijkstra
1 sibling, 0 replies; 12+ messages in thread
From: Wilco Dijkstra @ 2022-07-05 11:34 UTC (permalink / raw)
To: Adhemerval Zanella, libc-alpha, Fangrui Song
> And also fixes the SINGLE_THREAD_P macro for SINGLE_THREAD_BY_GLOBAL,
> since header inclusion single-thread.h is in the wrong order, the define
> needs to come before including sysdeps/unix/sysdep.h. The macro
> is now moved to a per-arch single-threade.h header.
>
> The SINGLE_THREAD_P is used on some more places.
>
> Checked on aarch64-linux-gnu and x86_64-linux-gnu.
LGTM
Cheers,
Wilco
---
nptl/Makefile | 1 -
nptl/allocatestack.c | 6 ----
nptl/libc_multiple_threads.c | 28 -------------------
nptl/pthread_cancel.c | 2 +-
posix/fork.c | 2 +-
sysdeps/nptl/setxid.h | 2 +-
.../unix/sysv/linux/aarch64/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/aarch64/sysdep.h | 2 --
sysdeps/unix/sysv/linux/alpha/sysdep.h | 2 --
sysdeps/unix/sysv/linux/arc/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/arc/sysdep.h | 2 --
sysdeps/unix/sysv/linux/arm/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/arm/sysdep.h | 2 --
sysdeps/unix/sysv/linux/hppa/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/hppa/sysdep.h | 2 --
.../sysv/linux/microblaze/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/microblaze/sysdep.h | 2 --
sysdeps/unix/sysv/linux/s390/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/s390/sysdep.h | 3 --
sysdeps/unix/sysv/linux/single-thread.h | 11 ++++----
.../unix/sysv/linux/x86_64/single-thread.h | 2 ++
sysdeps/unix/sysv/linux/x86_64/sysdep.h | 2 --
22 files changed, 22 insertions(+), 61 deletions(-)
delete mode 100644 nptl/libc_multiple_threads.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/single-thread.h
create mode 100644 sysdeps/unix/sysv/linux/arc/single-thread.h
create mode 100644 sysdeps/unix/sysv/linux/arm/single-thread.h
create mode 100644 sysdeps/unix/sysv/linux/hppa/single-thread.h
create mode 100644 sysdeps/unix/sysv/linux/microblaze/single-thread.h
create mode 100644 sysdeps/unix/sysv/linux/s390/single-thread.h
create mode 100644 sysdeps/unix/sysv/linux/x86_64/single-thread.h
diff --git a/nptl/Makefile b/nptl/Makefile
index b585663974..3d2ce8af8a 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -50,7 +50,6 @@ routines = \
events \
futex-internal \
libc-cleanup \
- libc_multiple_threads \
lowlevellock \
nptl-stack \
nptl_deallocate_tsd \
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c
index 01a282f3f6..98f5f6dd85 100644
--- a/nptl/allocatestack.c
+++ b/nptl/allocatestack.c
@@ -292,9 +292,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
/* This is at least the second thread. */
pd->header.multiple_threads = 1;
-#ifndef TLS_MULTIPLE_THREADS_IN_TCB
- __libc_multiple_threads = 1;
-#endif
#ifdef NEED_DL_SYSINFO
SETUP_THREAD_SYSINFO (pd);
@@ -413,9 +410,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
/* This is at least the second thread. */
pd->header.multiple_threads = 1;
-#ifndef TLS_MULTIPLE_THREADS_IN_TCB
- __libc_multiple_threads = 1;
-#endif
#ifdef NEED_DL_SYSINFO
SETUP_THREAD_SYSINFO (pd);
diff --git a/nptl/libc_multiple_threads.c b/nptl/libc_multiple_threads.c
deleted file mode 100644
index 0c2dc33d0d..0000000000
--- a/nptl/libc_multiple_threads.c
+++ /dev/null
@@ -1,28 +0,0 @@
-/* Copyright (C) 2002-2022 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#include <pthreadP.h>
-
-#if IS_IN (libc)
-# ifndef TLS_MULTIPLE_THREADS_IN_TCB
-/* Variable set to a nonzero value either if more than one thread runs or ran,
- or if a single-threaded process is trying to cancel itself. See
- nptl/descr.h for more context on the single-threaded process case. */
-int __libc_multiple_threads;
-libc_hidden_data_def (__libc_multiple_threads)
-# endif
-#endif
diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c
index e67b2df5cc..459317df49 100644
--- a/nptl/pthread_cancel.c
+++ b/nptl/pthread_cancel.c
@@ -161,7 +161,7 @@ __pthread_cancel (pthread_t th)
points get executed. */
THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
#ifndef TLS_MULTIPLE_THREADS_IN_TCB
- __libc_multiple_threads = 1;
+ __libc_single_threaded_internal = 0;
#endif
}
while (!atomic_compare_exchange_weak_acquire (&pd->cancelhandling, &oldval,
diff --git a/posix/fork.c b/posix/fork.c
index 987916a175..cee5ae83c8 100644
--- a/posix/fork.c
+++ b/posix/fork.c
@@ -45,7 +45,7 @@ __libc_fork (void)
requirement for fork (Austin Group tracker issue #62) this is
best effort to make is async-signal-safe at least for single-thread
case. */
- bool multiple_threads = __libc_single_threaded_internal == 0;
+ bool multiple_threads = !SINGLE_THREAD_P;
uint64_t lastrun;
lastrun = __run_prefork_handlers (multiple_threads);
diff --git a/sysdeps/nptl/setxid.h b/sysdeps/nptl/setxid.h
index b87cad7b18..3a412179ac 100644
--- a/sysdeps/nptl/setxid.h
+++ b/sysdeps/nptl/setxid.h
@@ -29,7 +29,7 @@
#define INLINE_SETXID_SYSCALL(name, nr, args...) \
({ \
int __result; \
- if (!__libc_single_threaded_internal) \
+ if (!SINGLE_THREAD_P) \
{ \
struct xid_command __cmd; \
__cmd.syscall_no = __NR_##name; \
diff --git a/sysdeps/unix/sysv/linux/aarch64/single-thread.h b/sysdeps/unix/sysv/linux/aarch64/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/aarch64/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/aarch64/sysdep.h b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
index 3b230dccf1..f1853e012f 100644
--- a/sysdeps/unix/sysv/linux/aarch64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
@@ -164,8 +164,6 @@
# define HAVE_CLOCK_GETTIME64_VSYSCALL "__kernel_clock_gettime"
# define HAVE_GETTIMEOFDAY_VSYSCALL "__kernel_gettimeofday"
-# define SINGLE_THREAD_BY_GLOBAL 1
-
# undef INTERNAL_SYSCALL_RAW
# define INTERNAL_SYSCALL_RAW(name, nr, args...) \
({ long _sys_result; \
diff --git a/sysdeps/unix/sysv/linux/alpha/sysdep.h b/sysdeps/unix/sysv/linux/alpha/sysdep.h
index 3051a744b4..77ec2b5400 100644
--- a/sysdeps/unix/sysv/linux/alpha/sysdep.h
+++ b/sysdeps/unix/sysv/linux/alpha/sysdep.h
@@ -32,8 +32,6 @@
#undef SYS_ify
#define SYS_ify(syscall_name) __NR_##syscall_name
-#define SINGLE_THREAD_BY_GLOBAL 1
-
#ifdef __ASSEMBLER__
#include <asm/pal.h>
#include <alpha/regdef.h>
diff --git a/sysdeps/unix/sysv/linux/arc/single-thread.h b/sysdeps/unix/sysv/linux/arc/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arc/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/arc/sysdep.h b/sysdeps/unix/sysv/linux/arc/sysdep.h
index 29b0e0161c..d0c1a78381 100644
--- a/sysdeps/unix/sysv/linux/arc/sysdep.h
+++ b/sysdeps/unix/sysv/linux/arc/sysdep.h
@@ -132,8 +132,6 @@ L (call_syscall_err): ASM_LINE_SEP \
#else /* !__ASSEMBLER__ */
-# define SINGLE_THREAD_BY_GLOBAL 1
-
# if IS_IN (libc)
extern long int __syscall_error (long int);
hidden_proto (__syscall_error)
diff --git a/sysdeps/unix/sysv/linux/arm/single-thread.h b/sysdeps/unix/sysv/linux/arm/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arm/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/arm/sysdep.h b/sysdeps/unix/sysv/linux/arm/sysdep.h
index 7bdd218063..1f270b961e 100644
--- a/sysdeps/unix/sysv/linux/arm/sysdep.h
+++ b/sysdeps/unix/sysv/linux/arm/sysdep.h
@@ -408,8 +408,6 @@ __local_syscall_error: \
#define INTERNAL_SYSCALL_NCS(number, nr, args...) \
INTERNAL_SYSCALL_RAW (number, nr, args)
-#define SINGLE_THREAD_BY_GLOBAL 1
-
#endif /* __ASSEMBLER__ */
#endif /* linux/arm/sysdep.h */
diff --git a/sysdeps/unix/sysv/linux/hppa/single-thread.h b/sysdeps/unix/sysv/linux/hppa/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/hppa/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/hppa/sysdep.h b/sysdeps/unix/sysv/linux/hppa/sysdep.h
index 42f7705852..2f339a4bd6 100644
--- a/sysdeps/unix/sysv/linux/hppa/sysdep.h
+++ b/sysdeps/unix/sysv/linux/hppa/sysdep.h
@@ -474,6 +474,4 @@ L(pre_end): ASM_LINE_SEP \
#define PTR_MANGLE(var) (void) (var)
#define PTR_DEMANGLE(var) (void) (var)
-#define SINGLE_THREAD_BY_GLOBAL 1
-
#endif /* _LINUX_HPPA_SYSDEP_H */
diff --git a/sysdeps/unix/sysv/linux/microblaze/single-thread.h b/sysdeps/unix/sysv/linux/microblaze/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/microblaze/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/microblaze/sysdep.h b/sysdeps/unix/sysv/linux/microblaze/sysdep.h
index dfd6312506..fda78f6467 100644
--- a/sysdeps/unix/sysv/linux/microblaze/sysdep.h
+++ b/sysdeps/unix/sysv/linux/microblaze/sysdep.h
@@ -308,8 +308,6 @@ SYSCALL_ERROR_LABEL_DCL: \
# define PTR_MANGLE(var) (void) (var)
# define PTR_DEMANGLE(var) (void) (var)
-# define SINGLE_THREAD_BY_GLOBAL 1
-
#undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
#define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
diff --git a/sysdeps/unix/sysv/linux/s390/single-thread.h b/sysdeps/unix/sysv/linux/s390/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/s390/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/s390/sysdep.h b/sysdeps/unix/sysv/linux/s390/sysdep.h
index 78c7e8c7e2..2d0a26779c 100644
--- a/sysdeps/unix/sysv/linux/s390/sysdep.h
+++ b/sysdeps/unix/sysv/linux/s390/sysdep.h
@@ -93,9 +93,6 @@
#define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
#define ASMFMT_6 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6), "d" (gpr7)
-#define SINGLE_THREAD_BY_GLOBAL 1
-
-
#define VDSO_NAME "LINUX_2.6.29"
#define VDSO_HASH 123718585
diff --git a/sysdeps/unix/sysv/linux/single-thread.h b/sysdeps/unix/sysv/linux/single-thread.h
index 4529a906d2..30dde4e81a 100644
--- a/sysdeps/unix/sysv/linux/single-thread.h
+++ b/sysdeps/unix/sysv/linux/single-thread.h
@@ -19,6 +19,10 @@
#ifndef _SINGLE_THREAD_H
#define _SINGLE_THREAD_H
+#ifndef __ASSEMBLER__
+# include <sys/single_threaded.h>
+#endif
+
/* The default way to check if the process is single thread is by using the
pthread_t 'multiple_threads' field. However, for some architectures it is
faster to either use an extra field on TCB or global variables (the TCB
@@ -27,16 +31,11 @@
The ABI might define SINGLE_THREAD_BY_GLOBAL to enable the single thread
check to use global variables instead of the pthread_t field. */
-#ifndef __ASSEMBLER__
-extern int __libc_multiple_threads;
-libc_hidden_proto (__libc_multiple_threads)
-#endif
-
#if !defined SINGLE_THREAD_BY_GLOBAL || IS_IN (rtld)
# define SINGLE_THREAD_P \
(THREAD_GETMEM (THREAD_SELF, header.multiple_threads) == 0)
#else
-# define SINGLE_THREAD_P (__libc_multiple_threads == 0)
+# define SINGLE_THREAD_P (__libc_single_threaded_internal != 0)
#endif
#define RTLD_SINGLE_THREAD_P SINGLE_THREAD_P
diff --git a/sysdeps/unix/sysv/linux/x86_64/single-thread.h b/sysdeps/unix/sysv/linux/x86_64/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86_64/single-thread.h
@@ -0,0 +1,2 @@
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/x86_64/sysdep.h b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
index e1ce3b62eb..740abefcfd 100644
--- a/sysdeps/unix/sysv/linux/x86_64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
@@ -379,8 +379,6 @@
# define HAVE_CLONE3_WRAPPER 1
-# define SINGLE_THREAD_BY_GLOBAL 1
-
#endif /* __ASSEMBLER__ */
--
2.34.1
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 4/4] Remove single-thread.h
2022-06-21 20:32 ` [PATCH v3 4/4] Remove single-thread.h Adhemerval Zanella
@ 2022-07-05 11:43 ` Wilco Dijkstra
0 siblings, 0 replies; 12+ messages in thread
From: Wilco Dijkstra @ 2022-07-05 11:43 UTC (permalink / raw)
To: Adhemerval Zanella, libc-alpha, Fangrui Song
> And move SINGLE_THREAD_P macro to sys/single_threaded.h.
LGTM
Cheers,
Wilco
---
include/sys/single_threaded.h | 13 ++++++--
sysdeps/generic/single-thread.h | 25 ----------------
sysdeps/mach/hurd/sysdep-cancel.h | 5 ----
sysdeps/unix/sysdep.h | 2 +-
.../unix/sysv/linux/aarch64/single-thread.h | 2 --
sysdeps/unix/sysv/linux/arc/single-thread.h | 2 --
sysdeps/unix/sysv/linux/arm/single-thread.h | 2 --
sysdeps/unix/sysv/linux/hppa/single-thread.h | 2 --
.../sysv/linux/microblaze/single-thread.h | 2 --
sysdeps/unix/sysv/linux/s390/single-thread.h | 2 --
sysdeps/unix/sysv/linux/single-thread.h | 30 -------------------
.../unix/sysv/linux/x86_64/single-thread.h | 2 --
12 files changed, 11 insertions(+), 78 deletions(-)
delete mode 100644 sysdeps/generic/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/aarch64/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/arc/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/arm/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/hppa/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/microblaze/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/s390/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/single-thread.h
delete mode 100644 sysdeps/unix/sysv/linux/x86_64/single-thread.h
diff --git a/include/sys/single_threaded.h b/include/sys/single_threaded.h
index 2015742be0..f42e40547e 100644
--- a/include/sys/single_threaded.h
+++ b/include/sys/single_threaded.h
@@ -1,6 +1,7 @@
-#include <misc/sys/single_threaded.h>
+#ifndef __ASSEMBLER__
+# include <misc/sys/single_threaded.h>
-#ifndef _ISOMAC
+# ifndef _ISOMAC
libc_hidden_proto_alias (__libc_single_threaded,
__libc_single_threaded_internal);
@@ -9,4 +10,10 @@ libc_hidden_proto_alias (__libc_single_threaded,
# define __libc_single_threaded_internal __libc_single_threaded
#endif
-#endif
+# define SINGLE_THREAD_P (__libc_single_threaded_internal != 0)
+
+# define RTLD_SINGLE_THREAD_P SINGLE_THREAD_P
+
+# endif
+
+#endif /* __ASSEMBLER__ */
diff --git a/sysdeps/generic/single-thread.h b/sysdeps/generic/single-thread.h
deleted file mode 100644
index 7f8222b38a..0000000000
--- a/sysdeps/generic/single-thread.h
+++ /dev/null
@@ -1,25 +0,0 @@
-/* Single thread optimization, generic version.
- Copyright (C) 2019-2022 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#ifndef _SINGLE_THREAD_H
-#define _SINGLE_THREAD_H
-
-#define SINGLE_THREAD_P (0)
-#define RTLD_SINGLE_THREAD_P (0)
-
-#endif /* _SINGLE_THREAD_H */
diff --git a/sysdeps/mach/hurd/sysdep-cancel.h b/sysdeps/mach/hurd/sysdep-cancel.h
index 669c17151a..9311367ab9 100644
--- a/sysdeps/mach/hurd/sysdep-cancel.h
+++ b/sysdeps/mach/hurd/sysdep-cancel.h
@@ -6,11 +6,6 @@ void __pthread_disable_asynccancel (int oldtype);
#pragma weak __pthread_enable_asynccancel
#pragma weak __pthread_disable_asynccancel
-/* Always multi-thread (since there's at least the sig handler), but no
- handling enabled. */
-#define SINGLE_THREAD_P (0)
-#define RTLD_SINGLE_THREAD_P (0)
-
#define LIBC_CANCEL_ASYNC() ({ \
int __cancel_oldtype = 0; \
if (__pthread_enable_asynccancel) \
diff --git a/sysdeps/unix/sysdep.h b/sysdeps/unix/sysdep.h
index a1d9df4c73..a8abecb92b 100644
--- a/sysdeps/unix/sysdep.h
+++ b/sysdeps/unix/sysdep.h
@@ -16,7 +16,7 @@
<https://www.gnu.org/licenses/>. */
#include <sysdeps/generic/sysdep.h>
-#include <single-thread.h>
+#include <sys/single_threaded.h>
#include <sys/syscall.h>
#define HAVE_SYSCALLS
diff --git a/sysdeps/unix/sysv/linux/aarch64/single-thread.h b/sysdeps/unix/sysv/linux/aarch64/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/aarch64/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/arc/single-thread.h b/sysdeps/unix/sysv/linux/arc/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/arc/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/arm/single-thread.h b/sysdeps/unix/sysv/linux/arm/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/arm/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/hppa/single-thread.h b/sysdeps/unix/sysv/linux/hppa/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/hppa/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/microblaze/single-thread.h b/sysdeps/unix/sysv/linux/microblaze/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/microblaze/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/s390/single-thread.h b/sysdeps/unix/sysv/linux/s390/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/s390/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/single-thread.h b/sysdeps/unix/sysv/linux/single-thread.h
deleted file mode 100644
index 2099848cf3..0000000000
--- a/sysdeps/unix/sysv/linux/single-thread.h
+++ /dev/null
@@ -1,30 +0,0 @@
-/* Single thread optimization, Linux version.
- Copyright (C) 2019-2022 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#ifndef _SINGLE_THREAD_H
-#define _SINGLE_THREAD_H
-
-#ifndef __ASSEMBLER__
-# include <sys/single_threaded.h>
-#endif
-
-#define SINGLE_THREAD_P (__libc_single_threaded_internal != 0)
-
-#define RTLD_SINGLE_THREAD_P SINGLE_THREAD_P
-
-#endif /* _SINGLE_THREAD_H */
diff --git a/sysdeps/unix/sysv/linux/x86_64/single-thread.h b/sysdeps/unix/sysv/linux/x86_64/single-thread.h
deleted file mode 100644
index a5d3a2aaf4..0000000000
--- a/sysdeps/unix/sysv/linux/x86_64/single-thread.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#define SINGLE_THREAD_BY_GLOBAL
-#include_next <single-thread.h>
--
2.34.1
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2022-07-05 11:43 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-21 20:32 [PATCH v3 0/4] Simplify internal single-threaded usage Adhemerval Zanella
2022-06-21 20:32 ` [PATCH v3 1/4] misc: Optimize internal usage of __libc_single_threaded Adhemerval Zanella
2022-06-23 4:15 ` Fangrui Song
2022-06-23 14:05 ` Adhemerval Zanella
2022-06-21 20:32 ` [PATCH v3 2/4] Replace __libc_multiple_threads with __libc_single_threaded Adhemerval Zanella
2022-06-22 11:04 ` Yann Droneaud
2022-06-22 12:24 ` Adhemerval Zanella
2022-06-22 13:53 ` Yann Droneaud
2022-07-05 11:34 ` Wilco Dijkstra
2022-06-21 20:32 ` [PATCH v3 3/4] Remove usage of TLS_MULTIPLE_THREADS_IN_TCB Adhemerval Zanella
2022-06-21 20:32 ` [PATCH v3 4/4] Remove single-thread.h Adhemerval Zanella
2022-07-05 11:43 ` Wilco Dijkstra
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