diff options
| author | Mike Belopuhov <mikeb@cvs.openbsd.org> | 2012-04-05 09:26:41 +0000 |
|---|---|---|
| committer | Mike Belopuhov <mikeb@cvs.openbsd.org> | 2012-04-05 09:26:41 +0000 |
| commit | bff1f2dca7be72c82459d905bdbfdaa51e626e2d (patch) | |
| tree | 7b3253cc4a4a0da9926f99ac0ea18a294fff203a /sys/msdosfs/denode.h | |
| parent | c57d49a44f485a5e0ffda5a16c469ef5b034d2ca (diff) | |
As it was made evident by Olaf 'Rhialto' Seibert in the NetBSD PR 34583,
caching the last cluster in the file before extending it considerably
speeds up further lookups. As a consequence this keeps write speed from
gradually decreasing and provides a measurable (up to 2x) performance
increase. Prompted by the diff from Alexander Polakov, ok miod, krw.
Diffstat (limited to 'sys/msdosfs/denode.h')
| -rw-r--r-- | sys/msdosfs/denode.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/sys/msdosfs/denode.h b/sys/msdosfs/denode.h index fde57a08ff2..9f17ac79edb 100644 --- a/sys/msdosfs/denode.h +++ b/sys/msdosfs/denode.h @@ -1,4 +1,4 @@ -/* $OpenBSD: denode.h,v 1.23 2010/07/17 19:27:07 guenther Exp $ */ +/* $OpenBSD: denode.h,v 1.24 2012/04/05 09:26:40 mikeb Exp $ */ /* $NetBSD: denode.h,v 1.24 1997/10/17 11:23:39 ws Exp $ */ /*- @@ -116,10 +116,11 @@ struct fatcache { * cache is probably pretty worthless if a file is opened by multiple * processes. */ -#define FC_SIZE 2 /* number of entries in the cache */ +#define FC_SIZE 3 /* number of entries in the cache */ #define FC_LASTMAP 0 /* entry the last call to pcbmap() resolved * to */ #define FC_LASTFC 1 /* entry for the last cluster in the file */ +#define FC_OLASTFC 2 /* entry for the previous last cluster */ #define FCE_EMPTY 0xffffffff /* doesn't represent an actual cluster # */ |