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| author | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2014-01-08 13:45:08 +0900 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2014-01-08 13:45:08 +0900 |
| commit | b1c57c1caa753cec299e62bb4272da0e85a01ef0 (patch) | |
| tree | 05d7338349557e5f62ca84a00c362bc669e50f90 /fs/f2fs/gc.h | |
| parent | fb5566da9181d33ecdd9892e44f90320e7d4cc9f (diff) | |
| download | blackbird-obmc-linux-b1c57c1caa753cec299e62bb4272da0e85a01ef0.tar.gz blackbird-obmc-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/gc.h')
| -rw-r--r-- | fs/f2fs/gc.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h index 507056d22205..5d5eb6047bf4 100644 --- a/fs/f2fs/gc.h +++ b/fs/f2fs/gc.h @@ -20,7 +20,7 @@ #define LIMIT_FREE_BLOCK 40 /* percentage over invalid + free space */ /* Search max. number of dirty segments to select a victim segment */ -#define MAX_VICTIM_SEARCH 4096 /* covers 8GB */ +#define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */ struct f2fs_gc_kthread { struct task_struct *f2fs_gc_task; |
