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Remove global device lock acquisition from dev_relthread(), replacing it

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with atomics on per-device data.
This commit is contained in:
Alexander Motin 2013-10-22 10:40:26 +00:00
parent 1a29adad30
commit 9e8bd2acf2
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=256885
1 changed files with 3 additions and 5 deletions
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8
sys/kern/kern_conf.c
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@ -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 cdev **devp, int *ref)
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