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| author | Jaegeuk Kim <jaegeuk@kernel.org> | 2014-09-10 16:53:02 -0700 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2014-09-16 04:10:44 -0700 |
| commit | c1ce1b02bb25640567dc484dc94d3a195d21e705 (patch) | |
| tree | 66d98ac24b6959a78618b1706f156f8f76614ad8 /Documentation/filesystems | |
| parent | a7ffdbe22cecaed59b5d76a5f003d68907d64240 (diff) | |
| download | linux-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.txt | 9 |
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 |