diff options
Diffstat (limited to 'nptl/sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S')
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S b/nptl/sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S index 3621efa4fc..21bf58cbbd 100644 --- a/nptl/sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S +++ b/nptl/sysdeps/unix/sysv/linux/x86_64/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 <drepper@redhat.com>, 2002. @@ -17,6 +17,8 @@ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ +#include <kernel-features.h> + /* 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 %fs:PRIVATE_FUTEX, reg +# define LOAD_FUTEX_WAKE(reg) \ + movl %fs:PRIVATE_FUTEX, reg ; \ + orl $FUTEX_WAKE, reg +#endif + #include "lowlevellock.S" |