Module Name: src
Committed By: dennis
Date: Wed Dec 24 19:56:49 UTC 2014
Modified Files:
src/sys/rump/include/rump: rump_namei.h
src/sys/sys: namei.h
Log Message:
Update stats-keeping in sys/kern/vfs_cache.c to remove (most)
races while allowing consistent lockless sampling of the per-cpu
statistics without atomic operations. Update comment describing
the locking protocol to include this.
To generate a diff of this commit:
cvs rdiff -u -r1.24 -r1.25 src/sys/rump/include/rump/rump_namei.h
cvs rdiff -u -r1.90 -r1.91 src/sys/sys/namei.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/rump/include/rump/rump_namei.h
diff -u src/sys/rump/include/rump/rump_namei.h:1.24 src/sys/rump/include/rump/rump_namei.h:1.25
--- src/sys/rump/include/rump/rump_namei.h:1.24 Tue Jun 3 21:16:37 2014
+++ src/sys/rump/include/rump/rump_namei.h Wed Dec 24 19:56:49 2014
@@ -1,11 +1,11 @@
-/* $NetBSD: rump_namei.h,v 1.24 2014/06/03 21:16:37 joerg Exp $ */
+/* $NetBSD: rump_namei.h,v 1.25 2014/12/24 19:56:49 dennis Exp $ */
/*
* WARNING: GENERATED FILE. DO NOT EDIT
* (edit namei.src and run make namei in src/sys/sys)
* by: NetBSD: gennameih.awk,v 1.5 2009/12/23 14:17:19 pooka Exp
- * from: NetBSD: namei.src,v 1.33 2014/06/03 21:16:15 joerg Exp
+ * from: NetBSD: namei.src,v 1.34 2014/12/24 19:50:04 dennis Exp
*/
#ifndef _RUMP_RUMP_NAMEI_H_
Index: src/sys/sys/namei.h
diff -u src/sys/sys/namei.h:1.90 src/sys/sys/namei.h:1.91
--- src/sys/sys/namei.h:1.90 Fri Sep 5 05:42:50 2014
+++ src/sys/sys/namei.h Wed Dec 24 19:56:49 2014
@@ -1,11 +1,11 @@
-/* $NetBSD: namei.h,v 1.90 2014/09/05 05:42:50 matt Exp $ */
+/* $NetBSD: namei.h,v 1.91 2014/12/24 19:56:49 dennis Exp $ */
/*
* WARNING: GENERATED FILE. DO NOT EDIT
* (edit namei.src and run make namei in src/sys/sys)
* by: NetBSD: gennameih.awk,v 1.5 2009/12/23 14:17:19 pooka Exp
- * from: NetBSD: namei.src,v 1.33 2014/06/03 21:16:15 joerg Exp
+ * from: NetBSD: namei.src,v 1.34 2014/12/24 19:50:04 dennis Exp
*/
/*
@@ -85,26 +85,6 @@ void pathbuf_stringcopy_put(struct pathb
int pathbuf_maybe_copyin(const char *userpath, enum uio_seg seg, struct pathbuf **ret);
/*
- * Lookup parameters: this structure describes the subset of
- * information from the nameidata structure that is passed
- * through the VOP interface.
- */
-struct componentname {
- /*
- * Arguments to lookup.
- */
- uint32_t cn_nameiop; /* namei operation */
- uint32_t cn_flags; /* flags to namei */
- kauth_cred_t cn_cred; /* credentials */
- /*
- * Shared between lookup and commit routines.
- */
- const char *cn_nameptr; /* pointer to looked up name */
- size_t cn_namelen; /* length of looked up comp */
- size_t cn_consume; /* chars to consume in lookup */
-};
-
-/*
* Encapsulation of namei parameters.
*/
struct nameidata {
@@ -135,7 +115,20 @@ struct nameidata {
* information from the nameidata structure that is passed
* through the VOP interface.
*/
- struct componentname ni_cnd;
+ struct componentname {
+ /*
+ * Arguments to lookup.
+ */
+ uint32_t cn_nameiop; /* namei operation */
+ uint32_t cn_flags; /* flags to namei */
+ kauth_cred_t cn_cred; /* credentials */
+ /*
+ * Shared between lookup and commit routines.
+ */
+ const char *cn_nameptr; /* pointer to looked up name */
+ size_t cn_namelen; /* length of looked up comp */
+ size_t cn_consume; /* chars to consume in lookup */
+ } ni_cnd;
};
/*
@@ -236,8 +229,8 @@ struct cpu_info;
extern pool_cache_t pnbuf_cache; /* pathname buffer cache */
-#define PNBUF_GET() ((char *)pool_cache_get(pnbuf_cache, PR_WAITOK))
-#define PNBUF_PUT(pnb) pool_cache_put(pnbuf_cache, (void *)(pnb))
+#define PNBUF_GET() pool_cache_get(pnbuf_cache, PR_WAITOK)
+#define PNBUF_PUT(pnb) pool_cache_put(pnbuf_cache, (pnb))
/*
* Typesafe flags for namei_simple/nameiat_simple.
@@ -303,38 +296,31 @@ void namecache_print(struct vnode *, voi
#endif
/*
- * Stats on usefulness of namei caches.
- * XXX: should be 64-bit counters.
- */
-struct nchstats {
- long ncs_goodhits; /* hits that we can really use */
- long ncs_neghits; /* negative hits that we can use */
- long ncs_badhits; /* hits we must drop */
- long ncs_falsehits; /* hits with id mismatch */
- long ncs_miss; /* misses */
- long ncs_long; /* long names that ignore cache */
- long ncs_pass2; /* names found with passes == 2 */
- long ncs_2passes; /* number of times we attempt it */
- long ncs_revhits; /* reverse-cache hits */
- long ncs_revmiss; /* reverse-cache misses */
-};
+ * Stats on usefulness of namei caches. A couple of structures are
+ * used for counting, with members having the same names but different
+ * types. Containerize member names with the preprocessor to avoid
+ * cut-'n'-paste. A (U) in the comment documents values that are
+ * incremented unlocked; we may treat these specially.
+ */
+#define _NAMEI_CACHE_STATS(type) { \
+ type ncs_goodhits; /* hits that we can really use (U) */ \
+ type ncs_neghits; /* negative hits that we can use */ \
+ type ncs_badhits; /* hits we must drop */ \
+ type ncs_falsehits; /* hits with id mismatch (U) */ \
+ type ncs_miss; /* misses */ \
+ type ncs_long; /* long names that ignore cache */ \
+ type ncs_pass2; /* names found with passes == 2 (U) */ \
+ type ncs_2passes; /* number of times we attempt it (U) */ \
+ type ncs_revhits; /* reverse-cache hits */ \
+ type ncs_revmiss; /* reverse-cache misses */ \
+}
-struct nchstats_sysctl {
- uint64_t ncs_goodhits; /* hits that we can really use */
- uint64_t ncs_neghits; /* negative hits that we can use */
- uint64_t ncs_badhits; /* hits we must drop */
- uint64_t ncs_falsehits; /* hits with id mismatch */
- uint64_t ncs_miss; /* misses */
- uint64_t ncs_long; /* long names that ignore cache */
- uint64_t ncs_pass2; /* names found with passes == 2 */
- uint64_t ncs_2passes; /* number of times we attempt it */
- uint64_t ncs_revhits; /* reverse-cache hits */
- uint64_t ncs_revmiss; /* reverse-cache misses */
-};
+/*
+ * Sysctl deals with a uint64_t version of the stats and summary
+ * totals are kept that way.
+ */
+struct nchstats _NAMEI_CACHE_STATS(uint64_t);
-#ifdef _KERNEL
-extern struct nchstats nchstats;
-#endif
/* #endif !_SYS_NAMEI_H_ (generated by gennameih.awk) */
/* Definitions match above, but with NAMEI_ prefix */
