Date: Sun, 5 Nov 2017 21:59:39 +0000 (UTC) From: Mateusz Guzik <mjg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r325451 - head/sys/kern Message-ID: <201711052159.vA5Lxdr3094281@repo.freebsd.org>
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Author: mjg Date: Sun Nov 5 21:59:39 2017 New Revision: 325451 URL: https://svnweb.freebsd.org/changeset/base/325451 Log: namecache: skip locking in cache_lookup_nomakeentry if there is no entry Modified: head/sys/kern/vfs_cache.c Modified: head/sys/kern/vfs_cache.c ============================================================================== --- head/sys/kern/vfs_cache.c Sun Nov 5 21:43:26 2017 (r325450) +++ head/sys/kern/vfs_cache.c Sun Nov 5 21:59:39 2017 (r325451) @@ -1163,6 +1163,9 @@ retry_dotdot: hash = cache_get_hash(cnp->cn_nameptr, cnp->cn_namelen, dvp); blp = HASH2BUCKETLOCK(hash); retry: + if (LIST_EMPTY(NCHHASH(hash))) + goto out_no_entry; + rw_rlock(blp); LIST_FOREACH(ncp, (NCHHASH(hash)), nc_hash) { @@ -1175,10 +1178,7 @@ retry: /* We failed to find an entry */ if (ncp == NULL) { rw_runlock(blp); - SDT_PROBE3(vfs, namecache, lookup, miss, dvp, cnp->cn_nameptr, - NULL); - counter_u64_add(nummisszap, 1); - return (0); + goto out_no_entry; } counter_u64_add(numposzaps, 1); @@ -1190,6 +1190,10 @@ retry: goto retry; } cache_free(ncp); + return (0); +out_no_entry: + SDT_PROBE3(vfs, namecache, lookup, miss, dvp, cnp->cn_nameptr, NULL); + counter_u64_add(nummisszap, 1); return (0); }
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