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authorJaegeuk Kim <jaegeuk@kernel.org>2014-09-10 16:53:02 -0700
committerJaegeuk Kim <jaegeuk@kernel.org>2014-09-16 04:10:44 -0700
commitc1ce1b02bb25640567dc484dc94d3a195d21e705 (patch)
tree66d98ac24b6959a78618b1706f156f8f76614ad8 /Documentation/filesystems
parenta7ffdbe22cecaed59b5d76a5f003d68907d64240 (diff)
downloadlinux-c1ce1b02bb25640567dc484dc94d3a195d21e705.tar.bz2
f2fs: give an option to enable in-place-updates during fsync to users
If user wrote F2FS_IPU_FSYNC:4 in /sys/fs/f2fs/ipu_policy, f2fs_sync_file only starts to try in-place-updates. And, if the number of dirty pages is over /sys/fs/f2fs/min_fsync_blocks, it keeps out-of-order manner. Otherwise, it triggers in-place-updates. This may be used by storage showing very high random write performance. For example, it can be used when, Seq. writes (Data) + wait + Seq. writes (Node) is pretty much slower than, Rand. writes (Data) Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/f2fs.txt9
1 files changed, 8 insertions, 1 deletions
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index a2046a7d0a9d..d010da85a769 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -194,13 +194,20 @@ Files in /sys/fs/f2fs/<devname>
updates in f2fs. There are five policies:
0: F2FS_IPU_FORCE, 1: F2FS_IPU_SSR,
2: F2FS_IPU_UTIL, 3: F2FS_IPU_SSR_UTIL,
- 4: F2FS_IPU_DISABLE.
+ 4: F2FS_IPU_FSYNC, 5: F2FS_IPU_DISABLE.
min_ipu_util This parameter controls the threshold to trigger
in-place-updates. The number indicates percentage
of the filesystem utilization, and used by
F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies.
+ min_fsync_blocks This parameter controls the threshold to trigger
+ in-place-updates when F2FS_IPU_FSYNC mode is set.
+ The number indicates the number of dirty pages
+ when fsync needs to flush on its call path. If
+ the number is less than this value, it triggers
+ in-place-updates.
+
max_victim_search This parameter controls the number of trials to
find a victim segment when conducting SSR and
cleaning operations. The default value is 4096