diff options
| author | jhb <jhb@FreeBSD.org> | 2000-11-29 18:41:19 +0000 |
|---|---|---|
| committer | jhb <jhb@FreeBSD.org> | 2000-11-29 18:41:19 +0000 |
| commit | 0640108ef5eaf64e213692ca07bbdebf5c080ec7 (patch) | |
| tree | 279c1ebe9a0dac7e8e1db06714f42de5d311b7d6 /sys/kern/kern_mutex.c | |
| parent | 42af0b6bb4a972d1a9696148a4a12dfe0a3ad03a (diff) | |
| download | FreeBSD-src-0640108ef5eaf64e213692ca07bbdebf5c080ec7.zip FreeBSD-src-0640108ef5eaf64e213692ca07bbdebf5c080ec7.tar.gz | |
Use an atomic operation with an appropriate memory barrier when releasing
a contested sleep mutex in the case that at least two processes are blocked
on the contested mutex.
Diffstat (limited to 'sys/kern/kern_mutex.c')
| -rw-r--r-- | sys/kern/kern_mutex.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c index 1a4dda2..a58311e 100644 --- a/sys/kern/kern_mutex.c +++ b/sys/kern/kern_mutex.c @@ -405,7 +405,8 @@ mtx_exit_hard(struct mtx *m, int type) _release_lock_quick(m); CTR1(KTR_LOCK, "mtx_exit: 0x%p not held", m); } else - m->mtx_lock = MTX_CONTESTED; + atomic_store_rel_ptr(&m->mtx_lock, + (void *)MTX_CONTESTED); pri = MAXPRI; LIST_FOREACH(m1, &p->p_contested, mtx_contested) { int cp = TAILQ_FIRST(&m1->mtx_blocked)->p_priority; |
