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* init.c (__pthread_initialize_minimal_internal): Optimize test

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FUTEX_CLOCK_REALTIME a bit.
This commit is contained in:
Ulrich Drepper 2009-01-04 18:10:04 +00:00
parent a9fa090b02
commit 3c612057ae
2 changed files with 25 additions and 16 deletions
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5
nptl/ChangeLog
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@ -1,3 +1,8 @@
2009-01-04 Ulrich Drepper <drepper@redhat.com>
* init.c (__pthread_initialize_minimal_internal): Optimize test
FUTEX_CLOCK_REALTIME a bit.
2009-01-03 Ulrich Drepper <drepper@redhat.com>
* init.c (__pthread_initialize_minimal_internal): Cheat a bit by

36
nptl/init.c
View File

@ -300,24 +300,28 @@ __pthread_initialize_minimal_internal (void)
if (!INTERNAL_SYSCALL_ERROR_P (word, err))
THREAD_SETMEM (pd, header.private_futex, FUTEX_PRIVATE_FLAG);
}
#endif
/* Private futexes have been introduced earlier than the
FUTEX_CLOCK_REALTIME flag. We don't have to run the test if we
know the former are not supported. This also means we know the
kernel will return ENOSYS for unknown operations. */
if (THREAD_GETMEM (pd, header.private_futex) != 0)
#endif
#ifndef __ASSUME_FUTEX_CLOCK_REALTIME
{
int word = 0;
/* NB: the syscall actually takes six parameters. The last is the
bit mask. But since we will not actually wait at all the value
is irrelevant. Given that passing six parameters is difficult
on some architectures we just pass whatever random value the
calling convention calls for to the kernel. It causes no harm. */
word = INTERNAL_SYSCALL (futex, err, 5, &word,
FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME
| FUTEX_PRIVATE_FLAG, 1, NULL, 0);
if (!INTERNAL_SYSCALL_ERROR_P (word, err)
|| (INTERNAL_SYSCALL_ERRNO (word, err) != ENOSYS
&& INTERNAL_SYSCALL_ERRNO (word, err) != EINVAL))
__set_futex_clock_realtime ();
}
{
int word = 0;
/* NB: the syscall actually takes six parameters. The last is the
bit mask. But since we will not actually wait at all the value
is irrelevant. Given that passing six parameters is difficult
on some architectures we just pass whatever random value the
calling convention calls for to the kernel. It causes no harm. */
word = INTERNAL_SYSCALL (futex, err, 5, &word,
FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME
| FUTEX_PRIVATE_FLAG, 1, NULL, 0);
assert (INTERNAL_SYSCALL_ERROR_P (word, err));
if (INTERNAL_SYSCALL_ERRNO (word, err) != ENOSYS)
__set_futex_clock_realtime ();
}
#endif
/* Set initial thread's stack block from 0 up to __libc_stack_end.