svn commit: r325458 - head/sys/kern

[Mateusz Guzik]

Author: mjg
Date: Sun Nov  5 22:29:45 2017
New Revision: 325458
URL: https://svnweb.freebsd.org/changeset/base/325458

Log:
  namecache: bump numcache after dropping all locks
  
  This makes no difference correctness-wise, but shortens total hold time.

Modified:
  head/sys/kern/vfs_cache.c

Modified: head/sys/kern/vfs_cache.c
==============================================================================
--- head/sys/kern/vfs_cache.c	Sun Nov  5 22:29:34 2017	(r325457)
+++ head/sys/kern/vfs_cache.c	Sun Nov  5 22:29:45 2017	(r325458)
@@ -1606,6 +1606,7 @@ cache_enter_time(struct vnode *dvp, struct vnode *vp, 
 	int flag;
 	int len;
 	bool neg_locked;
+	int lnumcache;
 
 	CTR3(KTR_VFS, "cache_enter(%p, %p, %s)", dvp, vp, cnp->cn_nameptr);
 	VNASSERT(vp == NULL || (vp->v_iflag & VI_DOOMED) == 0, vp,
@@ -1745,7 +1746,6 @@ cache_enter_time(struct vnode *dvp, struct vnode *vp, 
 		dvp->v_cache_dd = ncp;
 	}
 
-	atomic_add_rel_long(&numcache, 1);
 	if (vp != NULL) {
 		if (vp->v_type == VDIR) {
 			if (flag != NCF_ISDOTDOT) {
@@ -1798,7 +1798,8 @@ cache_enter_time(struct vnode *dvp, struct vnode *vp, 
 		    ncp->nc_name);
 	}
 	cache_enter_unlock(&cel);
-	if (numneg * ncnegfactor > numcache)
+	lnumcache = atomic_fetchadd_long(&numcache, 1) + 1;
+	if (numneg * ncnegfactor > lnumcache)
 		cache_negative_zap_one();
 	cache_free(ndd);
 	return;