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| author | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2014-01-08 05:45:08 +0100 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2014-01-08 05:45:08 +0100 |
| commit | b1c57c1caa753cec299e62bb4272da0e85a01ef0 (patch) | |
| tree | 05d7338349557e5f62ca84a00c362bc669e50f90 /fs/f2fs/f2fs.h | |
| parent | f2fs: improve write performance under frequent fsync calls (diff) | |
| download | linux-b1c57c1caa753cec299e62bb4272da0e85a01ef0.tar.xz linux-b1c57c1caa753cec299e62bb4272da0e85a01ef0.zip | |
f2fs: add a sysfs entry to control max_victim_search
Previously during SSR and GC, the maximum number of retrials to find a victim
segment was hard-coded by MAX_VICTIM_SEARCH, 4096 by default.
This number makes an effect on IO locality, when SSR mode is activated, which
results in performance fluctuation on some low-end devices.
If max_victim_search = 4, the victim will be searched like below.
("D" represents a dirty segment, and "*" indicates a selected victim segment.)
D1 D2 D3 D4 D5 D6 D7 D8 D9
[ * ]
[ * ]
[ * ]
[ ....]
This patch adds a sysfs entry to control the number dynamically through:
/sys/fs/f2fs/$dev/max_victim_search
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Diffstat (limited to 'fs/f2fs/f2fs.h')
| -rw-r--r-- | fs/f2fs/f2fs.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index b69f190fb195..5f7dc4f6eb09 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -451,6 +451,9 @@ struct f2fs_sb_info { struct f2fs_gc_kthread *gc_thread; /* GC thread */ unsigned int cur_victim_sec; /* current victim section num */ + /* maximum # of trials to find a victim segment for SSR and GC */ + unsigned int max_victim_search; + /* * for stat information. * one is for the LFS mode, and the other is for the SSR mode. |