From 5a8075b116280d0c1ece277e4be75250efca45b2 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Wed, 23 May 2007 20:51:45 +0000 Subject: * init.c (__pthread_initialize_minimal_internal): Check whether private futexes are available. * allocatestack.c (allocate_stack): Copy private_futex field from current thread into the new stack. * sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S: Use private futexes if they are available. * sysdeps/unix/sysv/linux/i386/i486/libc-lowlevellock.S: Likewise * sysdeps/unix/sysv/linux/x86_64/lowlevellock.S: Adjust so that change in libc-lowlevellock.S allow using private futexes. * sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/lowlevellock.h: Define FUTEX_PRIVATE_FLAG. * sysdeps/unix/sysv/linux/i386/lowlevellock.h: Likewise. * sysdeps/unix/sysv/linux/x86_64/pthread_once.S: Use private futexes if they are available. * sysdeps/unix/sysv/linux/i386/pthread_once.S: Likewise. * sysdeps/x86_64/tcb-offsets.sym: Add PRIVATE_FUTEX. * sysdeps/i386/tcb-offsets.sym: Likewise. * sysdeps/x86_64/tls.h (tcbhead_t): Add private_futex field. * sysdeps/i386/tls.h (tcbhead_t): Likewise. --- .../unix/sysv/linux/i386/i486/libc-lowlevellock.S | 17 ++++++++++++- .../unix/sysv/linux/i386/i486/lowlevellock.S | 28 +++++++++++++++++----- 2 files changed, 38 insertions(+), 7 deletions(-) (limited to 'nptl/sysdeps/unix/sysv/linux/i386/i486') diff --git a/nptl/sysdeps/unix/sysv/linux/i386/i486/libc-lowlevellock.S b/nptl/sysdeps/unix/sysv/linux/i386/i486/libc-lowlevellock.S index 88885b735d..f246711489 100644 --- a/nptl/sysdeps/unix/sysv/linux/i386/i486/libc-lowlevellock.S +++ b/nptl/sysdeps/unix/sysv/linux/i386/i486/libc-lowlevellock.S @@ -1,4 +1,4 @@ -/* Copyright (C) 2002, 2003 Free Software Foundation, Inc. +/* Copyright (C) 2002, 2003, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 2002. @@ -17,6 +17,8 @@ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ +#include + /* In libc.so we do not unconditionally use the lock prefix. Only if the application is using threads. */ #ifndef UP @@ -27,4 +29,17 @@ 0: #endif +/* All locks in libc are private. Use the kernel feature if possible. */ +#define FUTEX_PRIVATE_FLAG 128 +#ifdef __ASSUME_PRIVATE_FUTEX +# define FUTEX_WAIT (0 | FUTEX_PRIVATE_FLAG) +# define FUTEX_WAKE (1 | FUTEX_PRIVATE_FLAG) +#else +# define LOAD_FUTEX_WAIT(reg) \ + movl %gs:PRIVATE_FUTEX, reg +# define LOAD_FUTEX_WAKE(reg) \ + movl %gs:PRIVATE_FUTEX, reg ; \ + orl $FUTEX_WAKE, reg +#endif + #include "lowlevellock.S" diff --git a/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S b/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S index e2da5b04cf..1c47b37bb0 100644 --- a/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S +++ b/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S @@ -1,4 +1,4 @@ -/* Copyright (C) 2002, 2003, 2004, 2006 Free Software Foundation, Inc. +/* Copyright (C) 2002, 2003, 2004, 2006, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 2002. @@ -32,8 +32,22 @@ #define SYS_gettimeofday __NR_gettimeofday #define SYS_futex 240 -#define FUTEX_WAIT 0 -#define FUTEX_WAKE 1 +#ifndef FUTEX_WAIT +# define FUTEX_WAIT 0 +# define FUTEX_WAKE 1 +#endif + +#ifndef LOAD_FUTEX_WAIT +# if FUTEX_WAIT == 0 +# define LOAD_FUTEX_WAIT(reg) \ + xorl reg, reg +# else +# define LOAD_FUTEX_WAIT(reg) \ + movl $FUTEX_WAIT, reg +# endif +# define LOAD_FUTEX_WAKE(reg) \ + movl $FUTEX_WAKE, reg +#endif .globl __lll_mutex_lock_wait @@ -55,7 +69,7 @@ __lll_mutex_lock_wait: movl $2, %edx movl %ecx, %ebx xorl %esi, %esi /* No timeout. */ - xorl %ecx, %ecx /* movl $FUTEX_WAIT, %ecx */ + LOAD_FUTEX_WAIT (%ecx) cmpl %edx, %eax /* NB: %edx == 2 */ jne 2f @@ -151,7 +165,7 @@ __lll_mutex_timedlock_wait: /* Futex call. */ movl %esp, %esi - xorl %ecx, %ecx /* movl $FUTEX_WAIT, %ecx */ + LOAD_FUTEX_WAIT (%ecx) movl $SYS_futex, %eax ENTER_KERNEL movl %eax, %ecx @@ -252,7 +266,7 @@ __lll_mutex_unlock_wake: movl %eax, %ebx movl $0, (%eax) - movl $FUTEX_WAKE, %ecx + LOAD_FUTEX_WAKE (%ecx) movl $1, %edx /* Wake one thread. */ movl $SYS_futex, %eax ENTER_KERNEL @@ -314,6 +328,8 @@ __lll_timedwait_tid: jz 4f movl %esp, %esi + /* XXX The kernel so far uses global futex for the wakeup at + all times. */ xorl %ecx, %ecx /* movl $FUTEX_WAIT, %ecx */ movl %ebp, %ebx movl $SYS_futex, %eax -- cgit v1.2.3