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authorJaegeuk Kim <jaegeuk.kim@samsung.com>2014-03-19 13:31:37 +0900
committerAndreas Blaesius <skate4life@gmx.de>2016-06-05 21:21:23 +0200
commitf5d6969c8d21f11e33e3a74e1c1a268370823bdb (patch)
treebaf1a81d88031f31e64965847cfd4bb34eb99d0d /Documentation
parent5bb62494371bf69afc6653f37c03e328e2efac1c (diff)
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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')
-rw-r--r--Documentation/ABI/testing/sysfs-fs-f2fs6
-rw-r--r--Documentation/filesystems/f2fs.txt4
2 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 32b0809..4ac2c25 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -55,3 +55,9 @@ Date: January 2014
Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
Description:
Controls the number of trials to find a victim segment.
+
+What: /sys/fs/f2fs/<disk>/ram_thresh
+Date: March 2014
+Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+ Controls the memory footprint used by f2fs.
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 89dd977..a920935 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -194,6 +194,10 @@ 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
================================================================================