Date: Sat, 18 Apr 2015 00:59:04 +0000 (UTC) From: Kirk McKusick <mckusick@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r281677 - head/sys/kern Message-ID: <201504180059.t3I0x4NT004986@svn.freebsd.org>
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Author: mckusick Date: Sat Apr 18 00:59:03 2015 New Revision: 281677 URL: https://svnweb.freebsd.org/changeset/base/281677 Log: More accurately collect name-cache statistics in sysctl functions sysctl_debug_hashstat_nchash() and sysctl_debug_hashstat_rawnchash(). These changes are in preparation for allowing changes in the size of the vnode hash tables driven by increases and decreases in the maximum number of vnodes in the system. Reviewed by: kib@ Phabric: D2265 Modified: head/sys/kern/vfs_cache.c Modified: head/sys/kern/vfs_cache.c ============================================================================== --- head/sys/kern/vfs_cache.c Sat Apr 18 00:53:52 2015 (r281676) +++ head/sys/kern/vfs_cache.c Sat Apr 18 00:59:03 2015 (r281677) @@ -323,29 +323,25 @@ static SYSCTL_NODE(_debug, OID_AUTO, has static int sysctl_debug_hashstat_rawnchash(SYSCTL_HANDLER_ARGS) { - int error; struct nchashhead *ncpp; struct namecache *ncp; - int n_nchash; - int count; + int i, error, n_nchash, *cntbuf; n_nchash = nchash + 1; /* nchash is max index, not count */ - if (!req->oldptr) + if (req->oldptr == NULL) return SYSCTL_OUT(req, 0, n_nchash * sizeof(int)); - - /* Scan hash tables for applicable entries */ - for (ncpp = nchashtbl; n_nchash > 0; n_nchash--, ncpp++) { - CACHE_RLOCK(); - count = 0; - LIST_FOREACH(ncp, ncpp, nc_hash) { - count++; - } - CACHE_RUNLOCK(); - error = SYSCTL_OUT(req, &count, sizeof(count)); - if (error) - return (error); - } - return (0); + cntbuf = malloc(n_nchash * sizeof(int), M_TEMP, M_ZERO | M_WAITOK); + CACHE_RLOCK(); + /* Scan hash tables counting entries */ + for (ncpp = nchashtbl, i = 0; i < n_nchash; ncpp++, i++) + LIST_FOREACH(ncp, ncpp, nc_hash) + cntbuf[i]++; + CACHE_RUNLOCK(); + for (error = 0, i = 0; i < n_nchash; i++) + if ((error = SYSCTL_OUT(req, &cntbuf[i], sizeof(int))) != 0) + break; + free(cntbuf, M_TEMP); + return (error); } SYSCTL_PROC(_debug_hashstat, OID_AUTO, rawnchash, CTLTYPE_INT|CTLFLAG_RD| CTLFLAG_MPSAFE, 0, 0, sysctl_debug_hashstat_rawnchash, "S,int", @@ -363,6 +359,7 @@ sysctl_debug_hashstat_nchash(SYSCTL_HAND if (!req->oldptr) return SYSCTL_OUT(req, 0, 4 * sizeof(int)); + CACHE_RLOCK(); n_nchash = nchash + 1; /* nchash is max index, not count */ used = 0; maxlength = 0; @@ -370,17 +367,16 @@ sysctl_debug_hashstat_nchash(SYSCTL_HAND /* Scan hash tables for applicable entries */ for (ncpp = nchashtbl; n_nchash > 0; n_nchash--, ncpp++) { count = 0; - CACHE_RLOCK(); LIST_FOREACH(ncp, ncpp, nc_hash) { count++; } - CACHE_RUNLOCK(); if (count) used++; if (maxlength < count) maxlength = count; } n_nchash = nchash + 1; + CACHE_RUNLOCK(); pct = (used * 100) / (n_nchash / 100); error = SYSCTL_OUT(req, &n_nchash, sizeof(n_nchash)); if (error)
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