* [PATCH v1 1/2] Benchtests: Add bench for pthread_spin_{try}lock and mutex_trylock
@ 2022-10-01 2:33 Noah Goldstein
2022-10-01 2:33 ` [PATCH v1 2/2] x86: Optimize pthread_spin_{try}lock.S Noah Goldstein
0 siblings, 1 reply; 6+ messages in thread
From: Noah Goldstein @ 2022-10-01 2:33 UTC (permalink / raw)
To: libc-alpha; +Cc: goldstein.w.n, hjl.tools, carlos
Reuses infrastructure from previous pthread_mutex_lock benchmarks to
test other performance sensitive functions.
---
benchtests/Makefile | 10 ++++-
...utex-locks.c => bench-pthread-lock-base.c} | 20 +++++-----
benchtests/bench-pthread-mutex-lock.c | 32 ++++++++++++++++
benchtests/bench-pthread-mutex-trylock.c | 37 +++++++++++++++++++
benchtests/bench-pthread-spin-lock.c | 30 +++++++++++++++
benchtests/bench-pthread-spin-trylock.c | 34 +++++++++++++++++
6 files changed, 151 insertions(+), 12 deletions(-)
rename benchtests/{bench-pthread-mutex-locks.c => bench-pthread-lock-base.c} (93%)
create mode 100644 benchtests/bench-pthread-mutex-lock.c
create mode 100644 benchtests/bench-pthread-mutex-trylock.c
create mode 100644 benchtests/bench-pthread-spin-lock.c
create mode 100644 benchtests/bench-pthread-spin-trylock.c
diff --git a/benchtests/Makefile b/benchtests/Makefile
index d99771be74..fc1cda7fc3 100644
--- a/benchtests/Makefile
+++ b/benchtests/Makefile
@@ -103,11 +103,19 @@ endif
bench-pthread := \
pthread-locks \
- pthread-mutex-locks \
+ pthread-mutex-lock \
+ pthread-mutex-trylock \
+ pthread-spin-lock \
+ pthread-spin-trylock \
pthread_once \
thread_create \
# bench-pthread
+LDLIBS-bench-pthread-mutex-lock += -lm
+LDLIBS-bench-pthread-mutex-trylock += -lm
+LDLIBS-bench-pthread-spin-lock += -lm
+LDLIBS-bench-pthread-spin-trylock += -lm
+
bench-string := \
ffs \
ffsll \
diff --git a/benchtests/bench-pthread-mutex-locks.c b/benchtests/bench-pthread-lock-base.c
similarity index 93%
rename from benchtests/bench-pthread-mutex-locks.c
rename to benchtests/bench-pthread-lock-base.c
index 1685b9dd1f..fac8a12b52 100644
--- a/benchtests/bench-pthread-mutex-locks.c
+++ b/benchtests/bench-pthread-lock-base.c
@@ -1,4 +1,4 @@
-/* Measure mutex_lock for different threads and critical sections.
+/* Measure lock functions for different threads and critical sections.
Copyright (C) 2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
@@ -17,7 +17,6 @@
<https://www.gnu.org/licenses/>. */
#define TEST_MAIN
-#define TEST_NAME "pthread-mutex-locks"
#define TIMEOUT (20 * 60)
#include <stdio.h>
@@ -31,8 +30,8 @@
#include "bench-timing.h"
#include "json-lib.h"
-static pthread_mutex_t lock;
-static pthread_mutexattr_t attr;
+static bench_lock_t lock;
+static bench_lock_attr_t attr;
static pthread_barrier_t barrier;
#define START_ITERS 1000
@@ -104,9 +103,9 @@ worker (void *v)
TIMING_NOW (start);
while (iters--)
{
- pthread_mutex_lock (&lock);
+ LOCK (&lock);
critical_section (crt_len);
- pthread_mutex_unlock (&lock);
+ UNLOCK (&lock);
non_critical_section (non_crt_len);
}
TIMING_NOW (stop);
@@ -123,7 +122,7 @@ do_one_test (int num_threads, int crt_len, int non_crt_len, long iters)
Worker_Params *p, params[num_threads];
pthread_t threads[num_threads];
- pthread_mutex_init (&lock, &attr);
+ LOCK_INIT (&lock, &attr);
pthread_barrier_init (&barrier, NULL, num_threads);
for (i = 0; i < num_threads; i++)
@@ -137,7 +136,7 @@ do_one_test (int num_threads, int crt_len, int non_crt_len, long iters)
for (i = 0; i < num_threads; i++)
pthread_join (threads[i], NULL);
- pthread_mutex_destroy (&lock);
+ LOCK_DESTROY (&lock);
pthread_barrier_destroy (&barrier);
mean = 0;
@@ -246,7 +245,7 @@ do_bench (void)
char name[128];
json_init (&json_ctx, 2, stdout);
- json_attr_object_begin (&json_ctx, "pthread_mutex_locks");
+ json_attr_object_begin (&json_ctx, TEST_NAME);
/* The thread config begins from 1, and increases by 2x until nprocs.
We also wants to test over-saturation case (1.25*nprocs). */
@@ -260,8 +259,7 @@ do_bench (void)
threads[th_conf++] = nprocs;
threads[th_conf++] = nprocs + nprocs / 4;
- pthread_mutexattr_init (&attr);
- pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_ADAPTIVE_NP);
+ LOCK_ATTR_INIT (&attr);
snprintf (name, sizeof name, "type=adaptive");
for (k = 0; k < (sizeof (non_crt_lens) / sizeof (int)); k++)
diff --git a/benchtests/bench-pthread-mutex-lock.c b/benchtests/bench-pthread-mutex-lock.c
new file mode 100644
index 0000000000..16556d4116
--- /dev/null
+++ b/benchtests/bench-pthread-mutex-lock.c
@@ -0,0 +1,32 @@
+/* Measure mutex_lock for different threads and critical sections.
+ Copyright (C) 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/>. */
+
+#define LOCK(lock) pthread_mutex_lock (lock)
+#define UNLOCK(lock) pthread_mutex_unlock (lock)
+#define LOCK_INIT(lock, attr) pthread_mutex_init (lock, attr)
+#define LOCK_DESTROY(lock) pthread_mutex_destroy (lock)
+#define LOCK_ATTR_INIT(attr) \
+ pthread_mutexattr_init (attr); \
+ pthread_mutexattr_settype (attr, PTHREAD_MUTEX_ADAPTIVE_NP);
+
+#define bench_lock_t pthread_mutex_t
+#define bench_lock_attr_t pthread_mutexattr_t
+
+#define TEST_NAME "pthread-mutex-lock"
+
+#include "bench-pthread-lock-base.c"
diff --git a/benchtests/bench-pthread-mutex-trylock.c b/benchtests/bench-pthread-mutex-trylock.c
new file mode 100644
index 0000000000..66318f499f
--- /dev/null
+++ b/benchtests/bench-pthread-mutex-trylock.c
@@ -0,0 +1,37 @@
+/* Measure mutex_trylock for different threads and critical sections.
+ Copyright (C) 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/>. */
+
+#define LOCK(lock) \
+ while (pthread_mutex_trylock (lock) != 0) \
+ { \
+ non_critical_section (non_crt_len); \
+ }
+
+#define UNLOCK(lock) pthread_mutex_unlock (lock)
+#define LOCK_INIT(lock, attr) pthread_mutex_init (lock, attr)
+#define LOCK_DESTROY(lock) pthread_mutex_destroy (lock)
+#define LOCK_ATTR_INIT(attr) \
+ pthread_mutexattr_init (attr); \
+ pthread_mutexattr_settype (attr, PTHREAD_MUTEX_ADAPTIVE_NP);
+
+#define bench_lock_t pthread_mutex_t
+#define bench_lock_attr_t pthread_mutexattr_t
+
+#define TEST_NAME "pthread-mutex-trylock"
+
+#include "bench-pthread-lock-base.c"
diff --git a/benchtests/bench-pthread-spin-lock.c b/benchtests/bench-pthread-spin-lock.c
new file mode 100644
index 0000000000..2174933d6b
--- /dev/null
+++ b/benchtests/bench-pthread-spin-lock.c
@@ -0,0 +1,30 @@
+/* Measure mutex_trylock for different threads and critical sections.
+ Copyright (C) 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/>. */
+
+#define LOCK(lock) pthread_spin_lock (lock)
+#define UNLOCK(lock) pthread_spin_unlock (lock)
+#define LOCK_INIT(lock, attr) pthread_spin_init (lock, *(attr))
+#define LOCK_DESTROY(lock) pthread_spin_destroy (lock)
+#define LOCK_ATTR_INIT(attr) *(attr) = 0
+
+#define bench_lock_t pthread_spinlock_t
+#define bench_lock_attr_t int
+
+#define TEST_NAME "pthread-spin-lock"
+
+#include "bench-pthread-lock-base.c"
diff --git a/benchtests/bench-pthread-spin-trylock.c b/benchtests/bench-pthread-spin-trylock.c
new file mode 100644
index 0000000000..49eb972761
--- /dev/null
+++ b/benchtests/bench-pthread-spin-trylock.c
@@ -0,0 +1,34 @@
+/* Measure spin_trylock for different threads and critical sections.
+ Copyright (C) 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/>. */
+
+#define LOCK(lock) \
+ while (pthread_spin_lock (lock) != 0) \
+ { \
+ non_critical_section (non_crt_len); \
+ }
+#define UNLOCK(lock) pthread_spin_unlock (lock)
+#define LOCK_INIT(lock, attr) pthread_spin_init (lock, *(attr))
+#define LOCK_DESTROY(lock) pthread_spin_destroy (lock)
+#define LOCK_ATTR_INIT(attr) *(attr) = 0
+
+#define bench_lock_t pthread_spinlock_t
+#define bench_lock_attr_t int
+
+#define TEST_NAME "pthread-spin-trylock"
+
+#include "bench-pthread-lock-base.c"
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v1 2/2] x86: Optimize pthread_spin_{try}lock.S
2022-10-01 2:33 [PATCH v1 1/2] Benchtests: Add bench for pthread_spin_{try}lock and mutex_trylock Noah Goldstein
@ 2022-10-01 2:33 ` Noah Goldstein
2022-10-01 4:13 ` [PATCH v2 1/2] Benchtests: Add bench for pthread_spin_{try}lock and mutex_trylock Noah Goldstein
0 siblings, 1 reply; 6+ messages in thread
From: Noah Goldstein @ 2022-10-01 2:33 UTC (permalink / raw)
To: libc-alpha; +Cc: goldstein.w.n, hjl.tools, carlos
Save a jmp on the lock path coming from an initial failure in
pthread_spin_lock.S. This costs 4-bytes of code but since the
function still fits in the same number of 16-byte blocks (default
function alignment) it does not have affect on the total binary size
of libc.so (unchanged after this commit).
pthread_spin_trylock was using a CAS when a simple xchg works which
is often more expensive.
Full check passes on x86-64.
---
sysdeps/x86_64/nptl/pthread_spin_lock.S | 23 +++++++++++++++-------
sysdeps/x86_64/nptl/pthread_spin_trylock.S | 18 ++++++++++++-----
2 files changed, 29 insertions(+), 12 deletions(-)
diff --git a/sysdeps/x86_64/nptl/pthread_spin_lock.S b/sysdeps/x86_64/nptl/pthread_spin_lock.S
index 44b837d9db..1e09e59b10 100644
--- a/sysdeps/x86_64/nptl/pthread_spin_lock.S
+++ b/sysdeps/x86_64/nptl/pthread_spin_lock.S
@@ -19,18 +19,27 @@
#include <shlib-compat.h>
ENTRY(__pthread_spin_lock)
-1: LOCK
- decl 0(%rdi)
- jne 2f
+ /* Always return zero. */
xor %eax, %eax
+ LOCK
+ decl 0(%rdi)
+ jne 1f
ret
.align 16
-2: rep
+1:
+ /* `rep nop` == `pause`. */
+ rep
nop
- cmpl $0, 0(%rdi)
- jg 1b
- jmp 2b
+ cmpl %eax, 0(%rdi)
+ jle 1b
+ /* Just repeat the `lock decl` logic here. The code size save
+ of jumping back to entry doesn't change how many 16-byte
+ chunks (default function alignment) that the code fits in. */
+ LOCK
+ decl 0(%rdi)
+ jne 1b
+ ret
END(__pthread_spin_lock)
versioned_symbol (libc, __pthread_spin_lock, pthread_spin_lock, GLIBC_2_34)
diff --git a/sysdeps/x86_64/nptl/pthread_spin_trylock.S b/sysdeps/x86_64/nptl/pthread_spin_trylock.S
index fffdb27dd9..a1f97cb420 100644
--- a/sysdeps/x86_64/nptl/pthread_spin_trylock.S
+++ b/sysdeps/x86_64/nptl/pthread_spin_trylock.S
@@ -20,13 +20,21 @@
#include <shlib-compat.h>
ENTRY(__pthread_spin_trylock)
- movl $1, %eax
xorl %ecx, %ecx
- lock
- cmpxchgl %ecx, (%rdi)
+ /* xchg has implicit LOCK prefix. */
+ xchgl %ecx, (%rdi)
+
+ /* Branch on result. Expectation is the use of trylock will be
+ branching on success/failure so this branch can be used to
+ to predict the coming branch. It has the benefit of
+ breaking the likely expensive memory dependency on (%rdi). */
+ cmpl $1, %ecx
+ jnz 1f
+ xorl %eax, %eax
+ ret
+1:
movl $EBUSY, %eax
- cmovel %ecx, %eax
- retq
+ ret
END(__pthread_spin_trylock)
versioned_symbol (libc, __pthread_spin_trylock, pthread_spin_trylock,
GLIBC_2_34)
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 1/2] Benchtests: Add bench for pthread_spin_{try}lock and mutex_trylock
2022-10-01 2:33 ` [PATCH v1 2/2] x86: Optimize pthread_spin_{try}lock.S Noah Goldstein
@ 2022-10-01 4:13 ` Noah Goldstein
2022-10-01 4:13 ` [PATCH v2 2/2] x86: Cleanup pthread_spin_{try}lock.S Noah Goldstein
2022-10-03 17:10 ` [PATCH v2 1/2] Benchtests: Add bench for pthread_spin_{try}lock and mutex_trylock H.J. Lu
0 siblings, 2 replies; 6+ messages in thread
From: Noah Goldstein @ 2022-10-01 4:13 UTC (permalink / raw)
To: libc-alpha; +Cc: goldstein.w.n, hjl.tools, carlos
Reuses infrastructure from previous pthread_mutex_lock benchmarks to
test other performance sensitive functions.
---
benchtests/Makefile | 10 ++++-
...utex-locks.c => bench-pthread-lock-base.c} | 20 +++++-----
benchtests/bench-pthread-mutex-lock.c | 32 ++++++++++++++++
benchtests/bench-pthread-mutex-trylock.c | 37 +++++++++++++++++++
benchtests/bench-pthread-spin-lock.c | 30 +++++++++++++++
benchtests/bench-pthread-spin-trylock.c | 34 +++++++++++++++++
6 files changed, 151 insertions(+), 12 deletions(-)
rename benchtests/{bench-pthread-mutex-locks.c => bench-pthread-lock-base.c} (93%)
create mode 100644 benchtests/bench-pthread-mutex-lock.c
create mode 100644 benchtests/bench-pthread-mutex-trylock.c
create mode 100644 benchtests/bench-pthread-spin-lock.c
create mode 100644 benchtests/bench-pthread-spin-trylock.c
diff --git a/benchtests/Makefile b/benchtests/Makefile
index d99771be74..fc1cda7fc3 100644
--- a/benchtests/Makefile
+++ b/benchtests/Makefile
@@ -103,11 +103,19 @@ endif
bench-pthread := \
pthread-locks \
- pthread-mutex-locks \
+ pthread-mutex-lock \
+ pthread-mutex-trylock \
+ pthread-spin-lock \
+ pthread-spin-trylock \
pthread_once \
thread_create \
# bench-pthread
+LDLIBS-bench-pthread-mutex-lock += -lm
+LDLIBS-bench-pthread-mutex-trylock += -lm
+LDLIBS-bench-pthread-spin-lock += -lm
+LDLIBS-bench-pthread-spin-trylock += -lm
+
bench-string := \
ffs \
ffsll \
diff --git a/benchtests/bench-pthread-mutex-locks.c b/benchtests/bench-pthread-lock-base.c
similarity index 93%
rename from benchtests/bench-pthread-mutex-locks.c
rename to benchtests/bench-pthread-lock-base.c
index 1685b9dd1f..fac8a12b52 100644
--- a/benchtests/bench-pthread-mutex-locks.c
+++ b/benchtests/bench-pthread-lock-base.c
@@ -1,4 +1,4 @@
-/* Measure mutex_lock for different threads and critical sections.
+/* Measure lock functions for different threads and critical sections.
Copyright (C) 2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
@@ -17,7 +17,6 @@
<https://www.gnu.org/licenses/>. */
#define TEST_MAIN
-#define TEST_NAME "pthread-mutex-locks"
#define TIMEOUT (20 * 60)
#include <stdio.h>
@@ -31,8 +30,8 @@
#include "bench-timing.h"
#include "json-lib.h"
-static pthread_mutex_t lock;
-static pthread_mutexattr_t attr;
+static bench_lock_t lock;
+static bench_lock_attr_t attr;
static pthread_barrier_t barrier;
#define START_ITERS 1000
@@ -104,9 +103,9 @@ worker (void *v)
TIMING_NOW (start);
while (iters--)
{
- pthread_mutex_lock (&lock);
+ LOCK (&lock);
critical_section (crt_len);
- pthread_mutex_unlock (&lock);
+ UNLOCK (&lock);
non_critical_section (non_crt_len);
}
TIMING_NOW (stop);
@@ -123,7 +122,7 @@ do_one_test (int num_threads, int crt_len, int non_crt_len, long iters)
Worker_Params *p, params[num_threads];
pthread_t threads[num_threads];
- pthread_mutex_init (&lock, &attr);
+ LOCK_INIT (&lock, &attr);
pthread_barrier_init (&barrier, NULL, num_threads);
for (i = 0; i < num_threads; i++)
@@ -137,7 +136,7 @@ do_one_test (int num_threads, int crt_len, int non_crt_len, long iters)
for (i = 0; i < num_threads; i++)
pthread_join (threads[i], NULL);
- pthread_mutex_destroy (&lock);
+ LOCK_DESTROY (&lock);
pthread_barrier_destroy (&barrier);
mean = 0;
@@ -246,7 +245,7 @@ do_bench (void)
char name[128];
json_init (&json_ctx, 2, stdout);
- json_attr_object_begin (&json_ctx, "pthread_mutex_locks");
+ json_attr_object_begin (&json_ctx, TEST_NAME);
/* The thread config begins from 1, and increases by 2x until nprocs.
We also wants to test over-saturation case (1.25*nprocs). */
@@ -260,8 +259,7 @@ do_bench (void)
threads[th_conf++] = nprocs;
threads[th_conf++] = nprocs + nprocs / 4;
- pthread_mutexattr_init (&attr);
- pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_ADAPTIVE_NP);
+ LOCK_ATTR_INIT (&attr);
snprintf (name, sizeof name, "type=adaptive");
for (k = 0; k < (sizeof (non_crt_lens) / sizeof (int)); k++)
diff --git a/benchtests/bench-pthread-mutex-lock.c b/benchtests/bench-pthread-mutex-lock.c
new file mode 100644
index 0000000000..16556d4116
--- /dev/null
+++ b/benchtests/bench-pthread-mutex-lock.c
@@ -0,0 +1,32 @@
+/* Measure mutex_lock for different threads and critical sections.
+ Copyright (C) 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/>. */
+
+#define LOCK(lock) pthread_mutex_lock (lock)
+#define UNLOCK(lock) pthread_mutex_unlock (lock)
+#define LOCK_INIT(lock, attr) pthread_mutex_init (lock, attr)
+#define LOCK_DESTROY(lock) pthread_mutex_destroy (lock)
+#define LOCK_ATTR_INIT(attr) \
+ pthread_mutexattr_init (attr); \
+ pthread_mutexattr_settype (attr, PTHREAD_MUTEX_ADAPTIVE_NP);
+
+#define bench_lock_t pthread_mutex_t
+#define bench_lock_attr_t pthread_mutexattr_t
+
+#define TEST_NAME "pthread-mutex-lock"
+
+#include "bench-pthread-lock-base.c"
diff --git a/benchtests/bench-pthread-mutex-trylock.c b/benchtests/bench-pthread-mutex-trylock.c
new file mode 100644
index 0000000000..66318f499f
--- /dev/null
+++ b/benchtests/bench-pthread-mutex-trylock.c
@@ -0,0 +1,37 @@
+/* Measure mutex_trylock for different threads and critical sections.
+ Copyright (C) 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/>. */
+
+#define LOCK(lock) \
+ while (pthread_mutex_trylock (lock) != 0) \
+ { \
+ non_critical_section (non_crt_len); \
+ }
+
+#define UNLOCK(lock) pthread_mutex_unlock (lock)
+#define LOCK_INIT(lock, attr) pthread_mutex_init (lock, attr)
+#define LOCK_DESTROY(lock) pthread_mutex_destroy (lock)
+#define LOCK_ATTR_INIT(attr) \
+ pthread_mutexattr_init (attr); \
+ pthread_mutexattr_settype (attr, PTHREAD_MUTEX_ADAPTIVE_NP);
+
+#define bench_lock_t pthread_mutex_t
+#define bench_lock_attr_t pthread_mutexattr_t
+
+#define TEST_NAME "pthread-mutex-trylock"
+
+#include "bench-pthread-lock-base.c"
diff --git a/benchtests/bench-pthread-spin-lock.c b/benchtests/bench-pthread-spin-lock.c
new file mode 100644
index 0000000000..2174933d6b
--- /dev/null
+++ b/benchtests/bench-pthread-spin-lock.c
@@ -0,0 +1,30 @@
+/* Measure mutex_trylock for different threads and critical sections.
+ Copyright (C) 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/>. */
+
+#define LOCK(lock) pthread_spin_lock (lock)
+#define UNLOCK(lock) pthread_spin_unlock (lock)
+#define LOCK_INIT(lock, attr) pthread_spin_init (lock, *(attr))
+#define LOCK_DESTROY(lock) pthread_spin_destroy (lock)
+#define LOCK_ATTR_INIT(attr) *(attr) = 0
+
+#define bench_lock_t pthread_spinlock_t
+#define bench_lock_attr_t int
+
+#define TEST_NAME "pthread-spin-lock"
+
+#include "bench-pthread-lock-base.c"
diff --git a/benchtests/bench-pthread-spin-trylock.c b/benchtests/bench-pthread-spin-trylock.c
new file mode 100644
index 0000000000..49eb972761
--- /dev/null
+++ b/benchtests/bench-pthread-spin-trylock.c
@@ -0,0 +1,34 @@
+/* Measure spin_trylock for different threads and critical sections.
+ Copyright (C) 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/>. */
+
+#define LOCK(lock) \
+ while (pthread_spin_lock (lock) != 0) \
+ { \
+ non_critical_section (non_crt_len); \
+ }
+#define UNLOCK(lock) pthread_spin_unlock (lock)
+#define LOCK_INIT(lock, attr) pthread_spin_init (lock, *(attr))
+#define LOCK_DESTROY(lock) pthread_spin_destroy (lock)
+#define LOCK_ATTR_INIT(attr) *(attr) = 0
+
+#define bench_lock_t pthread_spinlock_t
+#define bench_lock_attr_t int
+
+#define TEST_NAME "pthread-spin-trylock"
+
+#include "bench-pthread-lock-base.c"
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 2/2] x86: Cleanup pthread_spin_{try}lock.S
2022-10-01 4:13 ` [PATCH v2 1/2] Benchtests: Add bench for pthread_spin_{try}lock and mutex_trylock Noah Goldstein
@ 2022-10-01 4:13 ` Noah Goldstein
2022-10-03 17:08 ` H.J. Lu
2022-10-03 17:10 ` [PATCH v2 1/2] Benchtests: Add bench for pthread_spin_{try}lock and mutex_trylock H.J. Lu
1 sibling, 1 reply; 6+ messages in thread
From: Noah Goldstein @ 2022-10-01 4:13 UTC (permalink / raw)
To: libc-alpha; +Cc: goldstein.w.n, hjl.tools, carlos
Save a jmp on the lock path coming from an initial failure in
pthread_spin_lock.S. This costs 4-bytes of code but since the
function still fits in the same number of 16-byte blocks (default
function alignment) it does not have affect on the total binary size
of libc.so (unchanged after this commit).
pthread_spin_trylock was using a CAS when a simple xchg works which
is often more expensive.
Full check passes on x86-64.
---
sysdeps/x86_64/nptl/pthread_spin_lock.S | 23 +++++++++++++++-------
sysdeps/x86_64/nptl/pthread_spin_trylock.S | 18 ++++++++++++-----
2 files changed, 29 insertions(+), 12 deletions(-)
diff --git a/sysdeps/x86_64/nptl/pthread_spin_lock.S b/sysdeps/x86_64/nptl/pthread_spin_lock.S
index 44b837d9db..1e09e59b10 100644
--- a/sysdeps/x86_64/nptl/pthread_spin_lock.S
+++ b/sysdeps/x86_64/nptl/pthread_spin_lock.S
@@ -19,18 +19,27 @@
#include <shlib-compat.h>
ENTRY(__pthread_spin_lock)
-1: LOCK
- decl 0(%rdi)
- jne 2f
+ /* Always return zero. */
xor %eax, %eax
+ LOCK
+ decl 0(%rdi)
+ jne 1f
ret
.align 16
-2: rep
+1:
+ /* `rep nop` == `pause`. */
+ rep
nop
- cmpl $0, 0(%rdi)
- jg 1b
- jmp 2b
+ cmpl %eax, 0(%rdi)
+ jle 1b
+ /* Just repeat the `lock decl` logic here. The code size save
+ of jumping back to entry doesn't change how many 16-byte
+ chunks (default function alignment) that the code fits in. */
+ LOCK
+ decl 0(%rdi)
+ jne 1b
+ ret
END(__pthread_spin_lock)
versioned_symbol (libc, __pthread_spin_lock, pthread_spin_lock, GLIBC_2_34)
diff --git a/sysdeps/x86_64/nptl/pthread_spin_trylock.S b/sysdeps/x86_64/nptl/pthread_spin_trylock.S
index fffdb27dd9..a1f97cb420 100644
--- a/sysdeps/x86_64/nptl/pthread_spin_trylock.S
+++ b/sysdeps/x86_64/nptl/pthread_spin_trylock.S
@@ -20,13 +20,21 @@
#include <shlib-compat.h>
ENTRY(__pthread_spin_trylock)
- movl $1, %eax
xorl %ecx, %ecx
- lock
- cmpxchgl %ecx, (%rdi)
+ /* xchg has implicit LOCK prefix. */
+ xchgl %ecx, (%rdi)
+
+ /* Branch on result. Expectation is the use of trylock will be
+ branching on success/failure so this branch can be used to
+ to predict the coming branch. It has the benefit of
+ breaking the likely expensive memory dependency on (%rdi). */
+ cmpl $1, %ecx
+ jnz 1f
+ xorl %eax, %eax
+ ret
+1:
movl $EBUSY, %eax
- cmovel %ecx, %eax
- retq
+ ret
END(__pthread_spin_trylock)
versioned_symbol (libc, __pthread_spin_trylock, pthread_spin_trylock,
GLIBC_2_34)
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 2/2] x86: Cleanup pthread_spin_{try}lock.S
2022-10-01 4:13 ` [PATCH v2 2/2] x86: Cleanup pthread_spin_{try}lock.S Noah Goldstein
@ 2022-10-03 17:08 ` H.J. Lu
0 siblings, 0 replies; 6+ messages in thread
From: H.J. Lu @ 2022-10-03 17:08 UTC (permalink / raw)
To: Noah Goldstein; +Cc: libc-alpha, carlos
On Fri, Sep 30, 2022 at 9:13 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> Save a jmp on the lock path coming from an initial failure in
> pthread_spin_lock.S. This costs 4-bytes of code but since the
> function still fits in the same number of 16-byte blocks (default
> function alignment) it does not have affect on the total binary size
> of libc.so (unchanged after this commit).
>
> pthread_spin_trylock was using a CAS when a simple xchg works which
> is often more expensive.
>
> Full check passes on x86-64.
> ---
> sysdeps/x86_64/nptl/pthread_spin_lock.S | 23 +++++++++++++++-------
> sysdeps/x86_64/nptl/pthread_spin_trylock.S | 18 ++++++++++++-----
> 2 files changed, 29 insertions(+), 12 deletions(-)
>
> diff --git a/sysdeps/x86_64/nptl/pthread_spin_lock.S b/sysdeps/x86_64/nptl/pthread_spin_lock.S
> index 44b837d9db..1e09e59b10 100644
> --- a/sysdeps/x86_64/nptl/pthread_spin_lock.S
> +++ b/sysdeps/x86_64/nptl/pthread_spin_lock.S
> @@ -19,18 +19,27 @@
> #include <shlib-compat.h>
>
> ENTRY(__pthread_spin_lock)
> -1: LOCK
> - decl 0(%rdi)
> - jne 2f
> + /* Always return zero. */
> xor %eax, %eax
> + LOCK
> + decl 0(%rdi)
> + jne 1f
> ret
>
> .align 16
> -2: rep
> +1:
> + /* `rep nop` == `pause`. */
> + rep
> nop
> - cmpl $0, 0(%rdi)
> - jg 1b
> - jmp 2b
> + cmpl %eax, 0(%rdi)
> + jle 1b
> + /* Just repeat the `lock decl` logic here. The code size save
> + of jumping back to entry doesn't change how many 16-byte
> + chunks (default function alignment) that the code fits in. */
> + LOCK
> + decl 0(%rdi)
> + jne 1b
> + ret
> END(__pthread_spin_lock)
> versioned_symbol (libc, __pthread_spin_lock, pthread_spin_lock, GLIBC_2_34)
>
> diff --git a/sysdeps/x86_64/nptl/pthread_spin_trylock.S b/sysdeps/x86_64/nptl/pthread_spin_trylock.S
> index fffdb27dd9..a1f97cb420 100644
> --- a/sysdeps/x86_64/nptl/pthread_spin_trylock.S
> +++ b/sysdeps/x86_64/nptl/pthread_spin_trylock.S
> @@ -20,13 +20,21 @@
> #include <shlib-compat.h>
>
> ENTRY(__pthread_spin_trylock)
> - movl $1, %eax
> xorl %ecx, %ecx
> - lock
> - cmpxchgl %ecx, (%rdi)
> + /* xchg has implicit LOCK prefix. */
> + xchgl %ecx, (%rdi)
> +
> + /* Branch on result. Expectation is the use of trylock will be
> + branching on success/failure so this branch can be used to
> + to predict the coming branch. It has the benefit of
> + breaking the likely expensive memory dependency on (%rdi). */
> + cmpl $1, %ecx
> + jnz 1f
> + xorl %eax, %eax
> + ret
> +1:
> movl $EBUSY, %eax
> - cmovel %ecx, %eax
> - retq
> + ret
> END(__pthread_spin_trylock)
> versioned_symbol (libc, __pthread_spin_trylock, pthread_spin_trylock,
> GLIBC_2_34)
> --
> 2.34.1
>
LGTM.
Thanks.
--
H.J.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/2] Benchtests: Add bench for pthread_spin_{try}lock and mutex_trylock
2022-10-01 4:13 ` [PATCH v2 1/2] Benchtests: Add bench for pthread_spin_{try}lock and mutex_trylock Noah Goldstein
2022-10-01 4:13 ` [PATCH v2 2/2] x86: Cleanup pthread_spin_{try}lock.S Noah Goldstein
@ 2022-10-03 17:10 ` H.J. Lu
1 sibling, 0 replies; 6+ messages in thread
From: H.J. Lu @ 2022-10-03 17:10 UTC (permalink / raw)
To: Noah Goldstein; +Cc: libc-alpha, carlos
On Fri, Sep 30, 2022 at 9:13 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> Reuses infrastructure from previous pthread_mutex_lock benchmarks to
> test other performance sensitive functions.
> ---
> benchtests/Makefile | 10 ++++-
> ...utex-locks.c => bench-pthread-lock-base.c} | 20 +++++-----
> benchtests/bench-pthread-mutex-lock.c | 32 ++++++++++++++++
> benchtests/bench-pthread-mutex-trylock.c | 37 +++++++++++++++++++
> benchtests/bench-pthread-spin-lock.c | 30 +++++++++++++++
> benchtests/bench-pthread-spin-trylock.c | 34 +++++++++++++++++
> 6 files changed, 151 insertions(+), 12 deletions(-)
> rename benchtests/{bench-pthread-mutex-locks.c => bench-pthread-lock-base.c} (93%)
> create mode 100644 benchtests/bench-pthread-mutex-lock.c
> create mode 100644 benchtests/bench-pthread-mutex-trylock.c
> create mode 100644 benchtests/bench-pthread-spin-lock.c
> create mode 100644 benchtests/bench-pthread-spin-trylock.c
>
> diff --git a/benchtests/Makefile b/benchtests/Makefile
> index d99771be74..fc1cda7fc3 100644
> --- a/benchtests/Makefile
> +++ b/benchtests/Makefile
> @@ -103,11 +103,19 @@ endif
>
> bench-pthread := \
> pthread-locks \
> - pthread-mutex-locks \
> + pthread-mutex-lock \
> + pthread-mutex-trylock \
> + pthread-spin-lock \
> + pthread-spin-trylock \
> pthread_once \
> thread_create \
> # bench-pthread
>
> +LDLIBS-bench-pthread-mutex-lock += -lm
> +LDLIBS-bench-pthread-mutex-trylock += -lm
> +LDLIBS-bench-pthread-spin-lock += -lm
> +LDLIBS-bench-pthread-spin-trylock += -lm
> +
> bench-string := \
> ffs \
> ffsll \
> diff --git a/benchtests/bench-pthread-mutex-locks.c b/benchtests/bench-pthread-lock-base.c
> similarity index 93%
> rename from benchtests/bench-pthread-mutex-locks.c
> rename to benchtests/bench-pthread-lock-base.c
> index 1685b9dd1f..fac8a12b52 100644
> --- a/benchtests/bench-pthread-mutex-locks.c
> +++ b/benchtests/bench-pthread-lock-base.c
> @@ -1,4 +1,4 @@
> -/* Measure mutex_lock for different threads and critical sections.
> +/* Measure lock functions for different threads and critical sections.
> Copyright (C) 2022 Free Software Foundation, Inc.
> This file is part of the GNU C Library.
>
> @@ -17,7 +17,6 @@
> <https://www.gnu.org/licenses/>. */
>
> #define TEST_MAIN
> -#define TEST_NAME "pthread-mutex-locks"
> #define TIMEOUT (20 * 60)
>
> #include <stdio.h>
> @@ -31,8 +30,8 @@
> #include "bench-timing.h"
> #include "json-lib.h"
>
> -static pthread_mutex_t lock;
> -static pthread_mutexattr_t attr;
> +static bench_lock_t lock;
> +static bench_lock_attr_t attr;
> static pthread_barrier_t barrier;
>
> #define START_ITERS 1000
> @@ -104,9 +103,9 @@ worker (void *v)
> TIMING_NOW (start);
> while (iters--)
> {
> - pthread_mutex_lock (&lock);
> + LOCK (&lock);
> critical_section (crt_len);
> - pthread_mutex_unlock (&lock);
> + UNLOCK (&lock);
> non_critical_section (non_crt_len);
> }
> TIMING_NOW (stop);
> @@ -123,7 +122,7 @@ do_one_test (int num_threads, int crt_len, int non_crt_len, long iters)
> Worker_Params *p, params[num_threads];
> pthread_t threads[num_threads];
>
> - pthread_mutex_init (&lock, &attr);
> + LOCK_INIT (&lock, &attr);
> pthread_barrier_init (&barrier, NULL, num_threads);
>
> for (i = 0; i < num_threads; i++)
> @@ -137,7 +136,7 @@ do_one_test (int num_threads, int crt_len, int non_crt_len, long iters)
> for (i = 0; i < num_threads; i++)
> pthread_join (threads[i], NULL);
>
> - pthread_mutex_destroy (&lock);
> + LOCK_DESTROY (&lock);
> pthread_barrier_destroy (&barrier);
>
> mean = 0;
> @@ -246,7 +245,7 @@ do_bench (void)
> char name[128];
>
> json_init (&json_ctx, 2, stdout);
> - json_attr_object_begin (&json_ctx, "pthread_mutex_locks");
> + json_attr_object_begin (&json_ctx, TEST_NAME);
>
> /* The thread config begins from 1, and increases by 2x until nprocs.
> We also wants to test over-saturation case (1.25*nprocs). */
> @@ -260,8 +259,7 @@ do_bench (void)
> threads[th_conf++] = nprocs;
> threads[th_conf++] = nprocs + nprocs / 4;
>
> - pthread_mutexattr_init (&attr);
> - pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_ADAPTIVE_NP);
> + LOCK_ATTR_INIT (&attr);
> snprintf (name, sizeof name, "type=adaptive");
>
> for (k = 0; k < (sizeof (non_crt_lens) / sizeof (int)); k++)
> diff --git a/benchtests/bench-pthread-mutex-lock.c b/benchtests/bench-pthread-mutex-lock.c
> new file mode 100644
> index 0000000000..16556d4116
> --- /dev/null
> +++ b/benchtests/bench-pthread-mutex-lock.c
> @@ -0,0 +1,32 @@
> +/* Measure mutex_lock for different threads and critical sections.
> + Copyright (C) 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/>. */
> +
> +#define LOCK(lock) pthread_mutex_lock (lock)
> +#define UNLOCK(lock) pthread_mutex_unlock (lock)
> +#define LOCK_INIT(lock, attr) pthread_mutex_init (lock, attr)
> +#define LOCK_DESTROY(lock) pthread_mutex_destroy (lock)
> +#define LOCK_ATTR_INIT(attr) \
> + pthread_mutexattr_init (attr); \
> + pthread_mutexattr_settype (attr, PTHREAD_MUTEX_ADAPTIVE_NP);
> +
> +#define bench_lock_t pthread_mutex_t
> +#define bench_lock_attr_t pthread_mutexattr_t
> +
> +#define TEST_NAME "pthread-mutex-lock"
> +
> +#include "bench-pthread-lock-base.c"
> diff --git a/benchtests/bench-pthread-mutex-trylock.c b/benchtests/bench-pthread-mutex-trylock.c
> new file mode 100644
> index 0000000000..66318f499f
> --- /dev/null
> +++ b/benchtests/bench-pthread-mutex-trylock.c
> @@ -0,0 +1,37 @@
> +/* Measure mutex_trylock for different threads and critical sections.
> + Copyright (C) 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/>. */
> +
> +#define LOCK(lock) \
> + while (pthread_mutex_trylock (lock) != 0) \
> + { \
> + non_critical_section (non_crt_len); \
> + }
> +
> +#define UNLOCK(lock) pthread_mutex_unlock (lock)
> +#define LOCK_INIT(lock, attr) pthread_mutex_init (lock, attr)
> +#define LOCK_DESTROY(lock) pthread_mutex_destroy (lock)
> +#define LOCK_ATTR_INIT(attr) \
> + pthread_mutexattr_init (attr); \
> + pthread_mutexattr_settype (attr, PTHREAD_MUTEX_ADAPTIVE_NP);
> +
> +#define bench_lock_t pthread_mutex_t
> +#define bench_lock_attr_t pthread_mutexattr_t
> +
> +#define TEST_NAME "pthread-mutex-trylock"
> +
> +#include "bench-pthread-lock-base.c"
> diff --git a/benchtests/bench-pthread-spin-lock.c b/benchtests/bench-pthread-spin-lock.c
> new file mode 100644
> index 0000000000..2174933d6b
> --- /dev/null
> +++ b/benchtests/bench-pthread-spin-lock.c
> @@ -0,0 +1,30 @@
> +/* Measure mutex_trylock for different threads and critical sections.
> + Copyright (C) 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/>. */
> +
> +#define LOCK(lock) pthread_spin_lock (lock)
> +#define UNLOCK(lock) pthread_spin_unlock (lock)
> +#define LOCK_INIT(lock, attr) pthread_spin_init (lock, *(attr))
> +#define LOCK_DESTROY(lock) pthread_spin_destroy (lock)
> +#define LOCK_ATTR_INIT(attr) *(attr) = 0
> +
> +#define bench_lock_t pthread_spinlock_t
> +#define bench_lock_attr_t int
> +
> +#define TEST_NAME "pthread-spin-lock"
> +
> +#include "bench-pthread-lock-base.c"
> diff --git a/benchtests/bench-pthread-spin-trylock.c b/benchtests/bench-pthread-spin-trylock.c
> new file mode 100644
> index 0000000000..49eb972761
> --- /dev/null
> +++ b/benchtests/bench-pthread-spin-trylock.c
> @@ -0,0 +1,34 @@
> +/* Measure spin_trylock for different threads and critical sections.
> + Copyright (C) 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/>. */
> +
> +#define LOCK(lock) \
> + while (pthread_spin_lock (lock) != 0) \
> + { \
> + non_critical_section (non_crt_len); \
> + }
> +#define UNLOCK(lock) pthread_spin_unlock (lock)
> +#define LOCK_INIT(lock, attr) pthread_spin_init (lock, *(attr))
> +#define LOCK_DESTROY(lock) pthread_spin_destroy (lock)
> +#define LOCK_ATTR_INIT(attr) *(attr) = 0
> +
> +#define bench_lock_t pthread_spinlock_t
> +#define bench_lock_attr_t int
> +
> +#define TEST_NAME "pthread-spin-trylock"
> +
> +#include "bench-pthread-lock-base.c"
> --
> 2.34.1
>
LGTM.
Thanks.
--
H.J.
^ permalink raw reply [flat|nested] 6+ messages in thread
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2022-10-01 2:33 [PATCH v1 1/2] Benchtests: Add bench for pthread_spin_{try}lock and mutex_trylock Noah Goldstein
2022-10-01 2:33 ` [PATCH v1 2/2] x86: Optimize pthread_spin_{try}lock.S Noah Goldstein
2022-10-01 4:13 ` [PATCH v2 1/2] Benchtests: Add bench for pthread_spin_{try}lock and mutex_trylock Noah Goldstein
2022-10-01 4:13 ` [PATCH v2 2/2] x86: Cleanup pthread_spin_{try}lock.S Noah Goldstein
2022-10-03 17:08 ` H.J. Lu
2022-10-03 17:10 ` [PATCH v2 1/2] Benchtests: Add bench for pthread_spin_{try}lock and mutex_trylock H.J. Lu
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