Module Name: src
Committed By: christos
Date: Fri Sep 13 13:58:53 UTC 2019
Modified Files:
src/sys/sys: namei.src
Log Message:
- make nc_nlen short since we can now accommodate more than len 256 names.
- reorder the struct to have the lists first for performance
- put name last and make it variable length
- add an assert to make sure we don't waster space
- bump the size we can store in the pool a little because we have more space
now because of alignment.
To generate a diff of this commit:
cvs rdiff -u -r1.42 -r1.43 src/sys/sys/namei.src
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/sys/namei.src
diff -u src/sys/sys/namei.src:1.42 src/sys/sys/namei.src:1.43
--- src/sys/sys/namei.src:1.42 Mon Jun 3 02:04:21 2019
+++ src/sys/sys/namei.src Fri Sep 13 09:58:53 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: namei.src,v 1.42 2019/06/03 06:04:21 msaitoh Exp $ */
+/* $NetBSD: namei.src,v 1.43 2019/09/13 13:58:53 christos Exp $ */
/*
* Copyright (c) 1985, 1989, 1991, 1993
@@ -187,20 +187,17 @@ NAMEIFL PARAMASK 0x02ee300 /* mask of pa
#endif
+#ifdef __NAMECACHE_PRIVATE
/*
- * This structure describes the elements in the cache of recent
- * names looked up by namei. NCHNAMLEN is sized to make structure
- * size a power of two to optimize allocations. Minimum reasonable
- * size is 15.
+ * For simplicity (and economy of storage), names longer than
+ * a maximum length of NCHNAMLEN are stored in non-pooled storage.
*/
-
-#define NCHNAMLEN 31 /* maximum name segment length we bother with */
+#define NCHNAMLEN 32 /* up to this size gets stored in pool */
/*
- * Namecache entry. This structure is arranged so that frequently
- * accessed and mostly read-only data is toward the front, with
- * infrequently accessed data and the lock towards the rear. The
- * lock is then more likely to be in a separate cache line.
+ * Namecache entry.
+ * This structure describes the elements in the cache of recent
+ * names looked up by namei.
*
* Locking rules:
*
@@ -214,18 +211,21 @@ NAMEIFL PARAMASK 0x02ee300 /* mask of pa
struct namecache {
LIST_ENTRY(namecache) nc_hash; /* L/C hash chain */
LIST_ENTRY(namecache) nc_vhash; /* L directory hash chain */
+ TAILQ_ENTRY(namecache) nc_lru; /* L pseudo-lru chain */
+ LIST_ENTRY(namecache) nc_dvlist;/* L dvp's list of cache entries */
+ LIST_ENTRY(namecache) nc_vlist; /* L vp's list of cache entries */
struct vnode *nc_dvp; /* N vnode of parent of name */
struct vnode *nc_vp; /* N vnode the name refers to */
- int nc_flags; /* - copy of componentname ISWHITEOUT */
- char nc_nlen; /* - length of name */
- char nc_name[NCHNAMLEN]; /* - segment name */
void *nc_gcqueue; /* N queue for garbage collection */
- TAILQ_ENTRY(namecache) nc_lru; /* L psuedo-lru chain */
- LIST_ENTRY(namecache) nc_dvlist;/* L dvp's list of cache entries */
- LIST_ENTRY(namecache) nc_vlist; /* L vp's list of cache entries */
kmutex_t nc_lock; /* lock on this entry */
int nc_hittime; /* N last time scored a hit */
+ int nc_flags; /* - copy of componentname ISWHITEOUT */
+ u_short nc_nlen; /* - length of name */
+ char nc_name[0]; /* - segment name */
};
+__CTASSERT((sizeof(struct namecache) + NCHNAMLEN)
+ % __alignof(struct namecache) == 0);
+#endif
#ifdef _KERNEL
#include <sys/pool.h>
