From: Andrew Morton <akpm@linux-foundation.org>
Date: Tue, 8 May 2007 07:23:49 +0000 (-0700)
Subject: mm: shrink parent dentries when shrinking slab
X-Git-Tag: v2.6.22-rc1~799
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=24c32d733dd44dbc5b9dcd0b8de58e16fdbeac76;p=linux-2.6

mm: shrink parent dentries when shrinking slab

Teach the dentry slab shrinker to aggressively shrink parent dentries when
shrinking the dentry cache.

This is done to attempt to improve the situation where the dentry slab cache
gets a lot of internal fragmentation due to pages containing directory
dentries.  It is expected that this change will cause some of those dentries
to be reaped earlier, and with less scanning.

Needs careful testing.

Cc: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/fs/dcache.c b/fs/dcache.c
index 681cab81b4..268da2e2bc 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -879,7 +879,7 @@ static int shrink_dcache_memory(int nr, gfp_t gfp_mask)
 	if (nr) {
 		if (!(gfp_mask & __GFP_FS))
 			return -1;
-		prune_dcache(nr, NULL, 0);
+		prune_dcache(nr, NULL, 1);
 	}
 	return (dentry_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;
 }