From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org, Lukasz Majewski <lukma@denx.de>,
Carlos O'Donell <carlos@redhat.com>
Subject: [PATCH 09/18] linux: Remove time64-support
Date: Thu, 17 Jun 2021 08:50:55 -0300 [thread overview]
Message-ID: <20210617115104.1359598-10-adhemerval.zanella@linaro.org> (raw)
In-Reply-To: <20210617115104.1359598-1-adhemerval.zanella@linaro.org>
It breaks the usage case of live migration like CRIU or similar
and most usages can be optimized away by either building glibc with
a minimum 5.1 kernel or by using the 32-bit syscall for the common
case.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
---
sysdeps/unix/sysv/linux/Makefile | 2 +-
sysdeps/unix/sysv/linux/time64-support.c | 23 --------
sysdeps/unix/sysv/linux/time64-support.h | 70 ------------------------
3 files changed, 1 insertion(+), 94 deletions(-)
delete mode 100644 sysdeps/unix/sysv/linux/time64-support.c
delete mode 100644 sysdeps/unix/sysv/linux/time64-support.h
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 710169a454..982755f980 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -61,7 +61,7 @@ sysdep_routines += adjtimex clone umount umount2 readahead sysctl \
open_by_handle_at mlock2 pkey_mprotect pkey_set pkey_get \
timerfd_gettime timerfd_settime prctl \
process_vm_readv process_vm_writev clock_adjtime \
- time64-support pselect32 select32 \
+ pselect32 select32 \
xstat fxstat lxstat xstat64 fxstat64 lxstat64 \
fxstatat fxstatat64 \
xmknod xmknodat convert_scm_timestamps
diff --git a/sysdeps/unix/sysv/linux/time64-support.c b/sysdeps/unix/sysv/linux/time64-support.c
deleted file mode 100644
index 0718e7421b..0000000000
--- a/sysdeps/unix/sysv/linux/time64-support.c
+++ /dev/null
@@ -1,23 +0,0 @@
-/* Auxiliary definitions for 64-bit time_t support.
- Copyright (C) 2020-2021 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 <time64-support.h>
-
-#ifndef __ASSUME_TIME64_SYSCALLS
-int __time64_support = 1;
-#endif
diff --git a/sysdeps/unix/sysv/linux/time64-support.h b/sysdeps/unix/sysv/linux/time64-support.h
deleted file mode 100644
index 8466d37f8f..0000000000
--- a/sysdeps/unix/sysv/linux/time64-support.h
+++ /dev/null
@@ -1,70 +0,0 @@
-/* Auxiliary definitions for 64-bit time_t support.
- Copyright (C) 2020-2021 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 <stdbool.h>
-#include <atomic.h>
-
-/* These helper functions are used to optimize the 64-bit time_t support on
- configurations that requires support for 32-bit time_t fallback
- (!__ASSUME_TIME64_SYSCALLS). The idea is once the kernel advertises that
- it does not have 64-bit time_t support, glibc will stop to try issue the
- 64-bit time_t syscall altogether.
-
- For instance:
-
- #ifndef __NR_symbol_time64
- # define __NR_symbol_time64 __NR_symbol
- #endif
- int r;
- if (supports_time64 ())
- {
- r = INLINE_SYSCALL_CALL (symbol, ...);
- if (r == 0 || errno != ENOSYS)
- return r;
-
- mark_time64_unsupported ();
- }
- #ifndef __ASSUME_TIME64_SYSCALLS
- <32-bit fallback syscall>
- #endif
- return r;
-
- On configuration with default 64-bit time_t this optimization should be
- optimized away by the compiler resulting in no overhead. */
-
-#ifndef __ASSUME_TIME64_SYSCALLS
-extern int __time64_support attribute_hidden;
-#endif
-
-static inline bool
-supports_time64 (void)
-{
-#ifdef __ASSUME_TIME64_SYSCALLS
- return true;
-#else
- return atomic_load_relaxed (&__time64_support) != 0;
-#endif
-}
-
-static inline void
-mark_time64_unsupported (void)
-{
-#ifndef __ASSUME_TIME64_SYSCALLS
- atomic_store_relaxed (&__time64_support, 0);
-#endif
-}
--
2.30.2
next prev parent reply other threads:[~2021-06-17 11:51 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-17 11:50 [PATCH 00/18] More y2038 fixes Adhemerval Zanella
2021-06-17 11:50 ` [PATCH 01/18] Use 64 bit time_t stat internally Adhemerval Zanella
2021-06-21 7:42 ` Lukasz Majewski
2021-06-22 19:37 ` Florian Weimer
2021-06-22 19:51 ` Adhemerval Zanella
2021-06-17 11:50 ` [PATCH 02/18] Use LFS and 64 bit time for installed programs Adhemerval Zanella
2021-06-17 12:19 ` Andreas Schwab
2021-06-18 18:50 ` Adhemerval Zanella
2021-06-17 20:49 ` Joseph Myers
2021-06-18 18:14 ` Adhemerval Zanella
2021-06-17 11:50 ` [PATCH 03/18] support: Add support_create_timer Adhemerval Zanella
2021-06-21 7:42 ` Lukasz Majewski
2021-06-17 11:50 ` [PATCH 04/18] linux: Only use 64-bit syscall if required for ppoll Adhemerval Zanella
2021-06-21 7:42 ` Lukasz Majewski
2021-06-17 11:50 ` [PATCH 05/18] linux: Only use 64-bit syscall if required for pselect Adhemerval Zanella
2021-06-21 7:42 ` Lukasz Majewski
2021-06-17 11:50 ` [PATCH 06/18] linux: Only use 64-bit syscall if required for select Adhemerval Zanella
2021-06-21 7:43 ` Lukasz Majewski
2021-06-17 11:50 ` [PATCH 07/18] linux: Remove supports_time64 () from clock_getres Adhemerval Zanella
2021-06-21 7:43 ` Lukasz Majewski
2021-06-17 11:50 ` [PATCH 08/18] linux: Remove supports_time64 () from clock_gettime Adhemerval Zanella
2021-06-21 7:43 ` Lukasz Majewski
2021-06-17 11:50 ` Adhemerval Zanella [this message]
2021-06-21 7:43 ` [PATCH 09/18] linux: Remove time64-support Lukasz Majewski
2021-06-17 11:50 ` [PATCH 10/18] linux: timerfd_gettime minor cleanup Adhemerval Zanella
2021-06-21 7:43 ` Lukasz Majewski
2021-06-17 11:50 ` [PATCH 11/18] linux: Only use 64-bit syscall if required for semtimedop Adhemerval Zanella
2021-06-21 7:43 ` Lukasz Majewski
2021-06-17 11:50 ` [PATCH 12/18] linux: Only use 64-bit syscall if required for timerfd_settime Adhemerval Zanella
2021-06-21 7:44 ` Lukasz Majewski
2021-06-17 11:50 ` [PATCH 13/18] linux: Only use 64-bit syscall if required for mq_timedreceive Adhemerval Zanella
2021-06-21 7:44 ` Lukasz Majewski
2021-06-17 11:51 ` [PATCH 14/18] linux: Only use 64-bit syscall if required for mq_timedsend Adhemerval Zanella
2021-06-21 7:44 ` Lukasz Majewski
2021-06-17 11:51 ` [PATCH 15/18] linux: Only use 64-bit syscall if required for sigtimedwait Adhemerval Zanella
2021-06-17 12:25 ` Andreas Schwab
2021-06-22 14:58 ` Adhemerval Zanella
2021-06-17 11:51 ` [PATCH 16/18] linux: Only use 64-bit syscall if required for utimensat family Adhemerval Zanella
2021-06-21 7:45 ` Lukasz Majewski
2021-06-17 11:51 ` [PATCH 17/18] linux: Only use 64-bit syscall if required for internal futex Adhemerval Zanella
2021-06-21 7:45 ` Lukasz Majewski
2021-06-17 11:51 ` [PATCH 18/18] linux: Only use 64-bit syscall if required for clock_nanosleep Adhemerval Zanella
2021-06-17 15:11 ` Lukasz Majewski
2021-06-17 17:45 ` Adhemerval Zanella
2021-06-21 7:46 ` Lukasz Majewski
2021-06-17 14:20 ` [PATCH 00/18] More y2038 fixes Lukasz Majewski
2021-06-17 17:41 ` Adhemerval Zanella
2021-06-17 20:58 ` Joseph Myers
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