Module Name: src
Committed By: ad
Date: Sun Feb 16 22:00:53 UTC 2020
Modified Files:
src/sys/kern [ad-namecache]: vfs_cache.c
Log Message:
Comments.
To generate a diff of this commit:
cvs rdiff -u -r1.126.2.11 -r1.126.2.12 src/sys/kern/vfs_cache.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/vfs_cache.c
diff -u src/sys/kern/vfs_cache.c:1.126.2.11 src/sys/kern/vfs_cache.c:1.126.2.12
--- src/sys/kern/vfs_cache.c:1.126.2.11 Fri Jan 24 16:48:59 2020
+++ src/sys/kern/vfs_cache.c Sun Feb 16 22:00:53 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_cache.c,v 1.126.2.11 2020/01/24 16:48:59 ad Exp $ */
+/* $NetBSD: vfs_cache.c,v 1.126.2.12 2020/02/16 22:00:53 ad Exp $ */
/*-
* Copyright (c) 2008, 2019, 2020 The NetBSD Foundation, Inc.
@@ -67,8 +67,9 @@
* reference. It is managed LRU, so frequently used names will hang
* around. The cache is indexed by hash value obtained from the name.
*
- * The name cache (or directory name lookup cache) is the brainchild of
- * Robert Elz and made its first appearance in 4.3BSD.
+ * The name cache is the brainchild of Robert Elz and was introduced in
+ * 4.3BSD. See "Using gprof to Tune the 4.2BSD Kernel", Marshall Kirk
+ * McKusick, May 21 1984.
*
* Data structures:
*
@@ -81,7 +82,7 @@
* The index is a red-black tree. There are no special concurrency
* requirements placed on it, because it's per-directory and protected
* by the namecache's per-directory locks. It should therefore not be
- * difficult to experiment with other data structures.
+ * difficult to experiment with other types of index.
*
* Each cached name is stored in a struct namecache, along with a
* pointer to the associated vnode (nc_vp). Names longer than a
@@ -170,7 +171,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_cache.c,v 1.126.2.11 2020/01/24 16:48:59 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_cache.c,v 1.126.2.12 2020/02/16 22:00:53 ad Exp $");
#define __NAMECACHE_PRIVATE
#ifdef _KERNEL_OPT
@@ -393,7 +394,7 @@ cache_remove(struct namecache *ncp, cons
}
/*
- * Find a single cache entry and return it. The vnode lock must be held.
+ * Find a single cache entry and return it. vi_nc_lock must be held.
*/
static struct namecache * __noinline
cache_lookup_entry(struct vnode *dvp, const char *name, size_t namelen,
@@ -1239,11 +1240,10 @@ cache_deactivate(void)
}
/*
- * Aim for a 1:1 ratio of active to inactive. It's a bit wet finger
- * in the air here, but this is to allow each potential victim a
- * reasonable amount of time to cycle through the inactive list in
- * order to score a hit and be reactivated, while trying not to
- * cause reactivations too frequently.
+ * Aim for a 1:1 ratio of active to inactive. This is to allow each
+ * potential victim a reasonable amount of time to cycle through the
+ * inactive list in order to score a hit and be reactivated, while
+ * trying not to cause reactivations too frequently.
*/
if (cache_lru.count[LRU_ACTIVE] < cache_lru.count[LRU_INACTIVE]) {
return;
