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| author | Ulrich Drepper <drepper@redhat.com> | 2009-01-04 18:10:04 +0000 |
|---|---|---|
| committer | Ulrich Drepper <drepper@redhat.com> | 2009-01-04 18:10:04 +0000 |
| commit | 3c612057ae7e7f4beac2ac793a85389d0116e6e2 (patch) | |
| tree | 1bf804ea30dcd877bd324a6b83f47ff6e569dce2 | |
| parent | a9fa090b02e37e1a1e0444722a1bca979a5b3426 (diff) | |
| download | glibc-3c612057ae7e7f4beac2ac793a85389d0116e6e2.tar.gz glibc-3c612057ae7e7f4beac2ac793a85389d0116e6e2.tar.xz glibc-3c612057ae7e7f4beac2ac793a85389d0116e6e2.zip | |
* init.c (__pthread_initialize_minimal_internal): Optimize test
FUTEX_CLOCK_REALTIME a bit.
| -rw-r--r-- | nptl/ChangeLog | 5 | ||||
| -rw-r--r-- | nptl/init.c | 36 |
2 files changed, 25 insertions, 16 deletions
diff --git a/nptl/ChangeLog b/nptl/ChangeLog index a55ad52d80..e25da8b640 100644 --- a/nptl/ChangeLog +++ b/nptl/ChangeLog @@ -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 diff --git a/nptl/init.c b/nptl/init.c index 05883af1f4..7a6dec5935 100644 --- a/nptl/init.c +++ b/nptl/init.c @@ -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. |