summaryrefslogtreecommitdiffstats
path: root/Documentation/filesystems
diff options
context:
space:
mode:
authorJaegeuk Kim2014-03-19 05:31:37 +0100
committerJaegeuk Kim2014-03-20 14:10:09 +0100
commitcdfc41c134d48c1923066bcfa6630b94588ad6bc (patch)
tree066af8a1d30379162ed299f3d30275f6e4809ab0 /Documentation/filesystems
parentf2fs: avoid to drop nat entries due to the negative nr_shrink (diff)
downloadkernel-qcow2-linux-cdfc41c134d48c1923066bcfa6630b94588ad6bc.tar.gz
kernel-qcow2-linux-cdfc41c134d48c1923066bcfa6630b94588ad6bc.tar.xz
kernel-qcow2-linux-cdfc41c134d48c1923066bcfa6630b94588ad6bc.zip
f2fs: throttle the memory footprint with a sysfs entry
This patch introduces ram_thresh, a sysfs entry, which controls the memory footprint used by the free nid list and the nat cache. Previously, the free nid list was controlled by MAX_FREE_NIDS, while the nat cache was managed by NM_WOUT_THRESHOLD. However, this approach cannot be applied dynamically according to the system. So, this patch adds ram_thresh that users can specify the threshold, which is in order of 1 / 1024. For example, if the total ram size is 4GB and the value is set to 10 by default, f2fs tries to control the number of free nids and nat caches not to consume over 10 * (4GB / 1024) = 10MB. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/f2fs.txt4
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 803784e1e8ef..f415b9fc4cc8 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -202,6 +202,10 @@ Files in /sys/fs/f2fs/<devname>
Otherwise, it needs to decrease this value to
reduce the space overhead. The default value is 0.
+ ram_thresh This parameter controls the memory footprint used
+ by free nids and cached nat entries. By default,
+ 10 is set, which indicates 10 MB / 1 GB RAM.
+
================================================================================
USAGE
================================================================================