From 83d87915da34fc02d170ff8c356406040da2823f Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Tue, 15 May 2007 06:24:31 +0000 Subject: [PATCH] * sysdeps/unix/sysv/linux/sem_post.c: Only wake threads if old value of semaphore was zero. * sysdeps/unix/sysv/linux/i386/i486/sem_post.S: Likewise. * sysdeps/unix/sysv/linux/powerpc/sem_post.c: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/sem_post.c: Likewise. * sysdeps/unix/sysv/linux/x86_64/sem_post.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/sem_wait.S: Remove unnecessary extra cancellation test. * sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S: Likewise. --- nptl/ChangeLog | 13 +++++++++++++ .../unix/sysv/linux/i386/i486/sem_post.S | 7 +++++-- .../unix/sysv/linux/powerpc/sem_post.c | 14 ++++++++------ nptl/sysdeps/unix/sysv/linux/sem_post.c | 14 ++++++++------ .../unix/sysv/linux/sparc/sparc32/sem_post.c | 13 ++++++++----- .../sysdeps/unix/sysv/linux/x86_64/sem_post.S | 9 ++++++--- .../unix/sysv/linux/x86_64/sem_timedwait.S | 19 +------------------ .../sysdeps/unix/sysv/linux/x86_64/sem_wait.S | 15 +-------------- 8 files changed, 50 insertions(+), 54 deletions(-) diff --git a/nptl/ChangeLog b/nptl/ChangeLog index 882d3e9b29..38ade7a96b 100644 --- a/nptl/ChangeLog +++ b/nptl/ChangeLog @@ -1,3 +1,16 @@ +2007-05-14 Ulrich Drepper + + * sysdeps/unix/sysv/linux/sem_post.c: Only wake threads if old + value of semaphore was zero. + * sysdeps/unix/sysv/linux/i386/i486/sem_post.S: Likewise. + * sysdeps/unix/sysv/linux/powerpc/sem_post.c: Likewise. + * sysdeps/unix/sysv/linux/sparc/sparc32/sem_post.c: Likewise. + * sysdeps/unix/sysv/linux/x86_64/sem_post.S: Likewise. + + * sysdeps/unix/sysv/linux/x86_64/sem_wait.S: Remove unnecessary + extra cancellation test. + * sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S: Likewise. + 2007-05-10 Ulrich Drepper * descr.h (struct pthread): Rearrange members to fill hole in diff --git a/nptl/sysdeps/unix/sysv/linux/i386/i486/sem_post.S b/nptl/sysdeps/unix/sysv/linux/i386/i486/sem_post.S index 71e96d2228..2813c20ef8 100644 --- a/nptl/sysdeps/unix/sysv/linux/i386/i486/sem_post.S +++ b/nptl/sysdeps/unix/sysv/linux/i386/i486/sem_post.S @@ -1,4 +1,4 @@ -/* Copyright (C) 2002, 2003, 2005 Free Software Foundation, Inc. +/* Copyright (C) 2002, 2003, 2005, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 2002. @@ -44,9 +44,12 @@ __new_sem_post: LOCK xaddl %edx, (%ebx) + testl %edx, %edx + jne 2f + movl $SYS_futex, %eax movl $FUTEX_WAKE, %ecx - addl $1, %edx + movl $1, %edx ENTER_KERNEL testl %eax, %eax diff --git a/nptl/sysdeps/unix/sysv/linux/powerpc/sem_post.c b/nptl/sysdeps/unix/sysv/linux/powerpc/sem_post.c index 91b9955181..86dd0ebb3b 100644 --- a/nptl/sysdeps/unix/sysv/linux/powerpc/sem_post.c +++ b/nptl/sysdeps/unix/sysv/linux/powerpc/sem_post.c @@ -1,5 +1,5 @@ /* sem_post -- post to a POSIX semaphore. Powerpc version. - Copyright (C) 2003, 2004 Free Software Foundation, Inc. + Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Paul Mackerras , 2003. @@ -32,12 +32,14 @@ __new_sem_post (sem_t *sem) int *futex = (int *) sem; __asm __volatile (__lll_rel_instr ::: "memory"); - int nr = atomic_increment_val (futex); - int err = lll_futex_wake (futex, nr); - if (__builtin_expect (err, 0) < 0) + if (atomic_increment_val (futex) == 1) { - __set_errno (-err); - return -1; + int err = lll_futex_wake (futex, 1); + if (__builtin_expect (err, 0) < 0) + { + __set_errno (-err); + return -1; + } } return 0; } diff --git a/nptl/sysdeps/unix/sysv/linux/sem_post.c b/nptl/sysdeps/unix/sysv/linux/sem_post.c index 671b43f7f7..641ce661a1 100644 --- a/nptl/sysdeps/unix/sysv/linux/sem_post.c +++ b/nptl/sysdeps/unix/sysv/linux/sem_post.c @@ -1,5 +1,5 @@ /* sem_post -- post to a POSIX semaphore. Generic futex-using version. - Copyright (C) 2003, 2004 Free Software Foundation, Inc. + Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Jakub Jelinek , 2003. @@ -31,12 +31,14 @@ __new_sem_post (sem_t *sem) { int *futex = (int *) sem; - int nr = atomic_increment_val (futex); - int err = lll_futex_wake (futex, nr); - if (__builtin_expect (err, 0) < 0) + if (atomic_increment_val (futex) == 1) { - __set_errno (-err); - return -1; + int err = lll_futex_wake (futex, 1); + if (__builtin_expect (err, 0) < 0) + { + __set_errno (-err); + return -1; + } } return 0; } diff --git a/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_post.c b/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_post.c index be1cc60b11..ba77aa90bd 100644 --- a/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_post.c +++ b/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_post.c @@ -1,5 +1,5 @@ /* sem_post -- post to a POSIX semaphore. SPARC version. - Copyright (C) 2003, 2004, 2006 Free Software Foundation, Inc. + Copyright (C) 2003, 2004, 2006, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Jakub Jelinek , 2003. @@ -39,11 +39,14 @@ __new_sem_post (sem_t *sem) nr = ++*futex; __sparc32_atomic_do_unlock24 (futex + 1); } - int err = lll_futex_wake (futex, nr); - if (__builtin_expect (err, 0) < 0) + if (nr == 1) { - __set_errno (-err); - return -1; + int err = lll_futex_wake (futex, 1); + if (__builtin_expect (err, 0) < 0) + { + __set_errno (-err); + return -1; + } } return 0; } diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/sem_post.S b/nptl/sysdeps/unix/sysv/linux/x86_64/sem_post.S index 7f608a5974..cc3a9a9cee 100644 --- a/nptl/sysdeps/unix/sysv/linux/x86_64/sem_post.S +++ b/nptl/sysdeps/unix/sysv/linux/x86_64/sem_post.S @@ -1,4 +1,4 @@ -/* Copyright (C) 2002, 2003, 2005 Free Software Foundation, Inc. +/* Copyright (C) 2002, 2003, 2005, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 2002. @@ -41,15 +41,18 @@ sem_post: LOCK xaddl %edx, (%rdi) + testl %edx, %edx + jne 2f + movl $SYS_futex, %eax movl $FUTEX_WAKE, %esi - incl %edx + movl $1, %edx syscall testq %rax, %rax js 1f - xorl %eax, %eax +2: xorl %eax, %eax retq 1: diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S b/nptl/sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S index c44d3f5e77..76a566b988 100644 --- a/nptl/sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S +++ b/nptl/sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S @@ -1,4 +1,4 @@ -/* Copyright (C) 2002, 2003, 2005 Free Software Foundation, Inc. +/* Copyright (C) 2002, 2003, 2005, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 2002. @@ -40,12 +40,6 @@ .align 16 cfi_startproc sem_timedwait: - /* First check for cancellation. */ - movl %fs:CANCELHANDLING, %eax - andl $0xfffffff9, %eax - cmpl $8, %eax - je 11f - movl (%rdi), %eax 2: testl %eax, %eax je 1f @@ -160,16 +154,5 @@ sem_timedwait: orl $-1, %eax jmp 10b - cfi_adjust_cfa_offset(-48) - cfi_restore(14) - cfi_restore(13) - cfi_restore(12) - -11: /* Canceled. */ - movq $0xffffffffffffffff, %fs:RESULT - LOCK - orl $0x10, %fs:CANCELHANDLING - movq %fs:CLEANUP_JMP_BUF, %rdi - jmp HIDDEN_JUMPTARGET (__pthread_unwind) cfi_endproc .size sem_timedwait,.-sem_timedwait diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S b/nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S index 63ecd063ab..5bd78eb944 100644 --- a/nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S +++ b/nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S @@ -1,4 +1,4 @@ -/* Copyright (C) 2002, 2003, 2005 Free Software Foundation, Inc. +/* Copyright (C) 2002, 2003, 2005, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 2002. @@ -37,12 +37,6 @@ .align 16 cfi_startproc sem_wait: - /* First check for cancellation. */ - movl %fs:CANCELHANDLING, %eax - andl $0xfffffff9, %eax - cmpl $8, %eax - je 4f - pushq %r12 cfi_adjust_cfa_offset(8) cfi_offset(12, -16) @@ -109,12 +103,5 @@ sem_wait: cfi_restore(12) retq - -4: /* Canceled. */ - movq $0xffffffffffffffff, %fs:RESULT - LOCK - orl $0x10, %fs:CANCELHANDLING - movq %fs:CLEANUP_JMP_BUF, %rdi - jmp HIDDEN_JUMPTARGET (__pthread_unwind) cfi_endproc .size sem_wait,.-sem_wait