[PATCH] vm: Document that setting vfs_cache_pressure to 0 isn't a good idea

From: Jan Kara
Date: Thu Jul 16 2009 - 12:57:36 EST


Reported-by: Christian Thaeter <ct@xxxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
Documentation/sysctl/vm.txt | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

Andrew, would you merge this please? Thanks.

diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index c4de635..76e8671 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -585,7 +585,9 @@ caching of directory and inode objects.
At the default value of vfs_cache_pressure=100 the kernel will attempt to
reclaim dentries and inodes at a "fair" rate with respect to pagecache and
swapcache reclaim. Decreasing vfs_cache_pressure causes the kernel to prefer
-to retain dentry and inode caches. Increasing vfs_cache_pressure beyond 100
+to retain dentry and inode caches. When vfs_cache_pressure=0, the kernel will
+never reclaim dentries and inodes due to memory pressure and this can easily
+lead to out-of-memory conditions. Increasing vfs_cache_pressure beyond 100
causes the kernel to prefer to reclaim dentries and inodes.

==============================================================
--
1.6.0.2

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