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| author | John Baldwin <jhb@FreeBSD.org> | 2006-04-14 19:51:50 +0000 |
|---|---|---|
| committer | John Baldwin <jhb@FreeBSD.org> | 2006-04-14 19:51:50 +0000 |
| commit | 76447e561824098fac205f10fbbacf1f1a13c81c (patch) | |
| tree | 60065c0baa090eb5c3d4da2678c940b19f4df51b | |
| parent | 1427d59beef1c498aca96589ea214e767fe76e70 (diff) | |
| download | src-76447e561824098fac205f10fbbacf1f1a13c81c.tar.gz src-76447e561824098fac205f10fbbacf1f1a13c81c.zip | |
Mark the thread pointer used during an adaptive spin volatile so that the
compiler doesn't decide to cache td_state. Cachine the state would cause
the spinning thread to not notice when the owning thread stopped executing
(if it was preempted for example) which could result in livelock.
Notes
Notes:
svn path=/head/; revision=157763
| -rw-r--r-- | sys/kern/kern_mutex.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c index 2b275d034417..be228d61b738 100644 --- a/sys/kern/kern_mutex.c +++ b/sys/kern/kern_mutex.c @@ -449,7 +449,7 @@ _mtx_lock_sleep(struct mtx *m, uintptr_t tid, int opts, const char *file, int line) { #if defined(SMP) && !defined(NO_ADAPTIVE_MUTEXES) - struct thread *owner; + volatile struct thread *owner; #endif uintptr_t v; #ifdef KTR |