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authorUlrich Drepper <drepper@redhat.com>2009-01-04 18:10:04 +0000
committerUlrich Drepper <drepper@redhat.com>2009-01-04 18:10:04 +0000
commit3c612057ae7e7f4beac2ac793a85389d0116e6e2 (patch)
tree1bf804ea30dcd877bd324a6b83f47ff6e569dce2
parenta9fa090b02e37e1a1e0444722a1bca979a5b3426 (diff)
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* init.c (__pthread_initialize_minimal_internal): Optimize test
FUTEX_CLOCK_REALTIME a bit.
-rw-r--r--nptl/ChangeLog5
-rw-r--r--nptl/init.c36
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.