svn commit: r256885 - head/sys/kern
Alexander Motin
mav at FreeBSD.org
Tue Oct 22 10:40:26 UTC 2013
Author: mav
Date: Tue Oct 22 10:40:26 2013
New Revision: 256885
URL: http://svnweb.freebsd.org/changeset/base/256885
Log:
Remove global device lock acquisition from dev_relthread(), replacing it
with atomics on per-device data.
Modified:
head/sys/kern/kern_conf.c
Modified: head/sys/kern/kern_conf.c
==============================================================================
--- head/sys/kern/kern_conf.c Tue Oct 22 10:21:20 2013 (r256884)
+++ head/sys/kern/kern_conf.c Tue Oct 22 10:40:26 2013 (r256885)
@@ -193,7 +193,7 @@ dev_refthread(struct cdev *dev, int *ref
if (csw != NULL) {
cdp = cdev2priv(dev);
if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
- dev->si_threadcount++;
+ atomic_add_long(&dev->si_threadcount, 1);
else
csw = NULL;
}
@@ -234,7 +234,7 @@ devvn_refthread(struct vnode *vp, struct
if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
csw = dev->si_devsw;
if (csw != NULL)
- dev->si_threadcount++;
+ atomic_add_long(&dev->si_threadcount, 1);
}
dev_unlock();
if (csw != NULL) {
@@ -251,11 +251,9 @@ dev_relthread(struct cdev *dev, int ref)
mtx_assert(&devmtx, MA_NOTOWNED);
if (!ref)
return;
- dev_lock();
KASSERT(dev->si_threadcount > 0,
("%s threadcount is wrong", dev->si_name));
- dev->si_threadcount--;
- dev_unlock();
+ atomic_subtract_rel_long(&dev->si_threadcount, 1);
}
int
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