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authorJaegeuk Kim <jaegeuk.kim@samsung.com>2014-01-08 13:45:08 +0900
committerJaegeuk Kim <jaegeuk.kim@samsung.com>2014-01-08 13:45:08 +0900
commitb1c57c1caa753cec299e62bb4272da0e85a01ef0 (patch)
tree05d7338349557e5f62ca84a00c362bc669e50f90 /fs/f2fs/gc.h
parentfb5566da9181d33ecdd9892e44f90320e7d4cc9f (diff)
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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.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
index 507056d..5d5eb60 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;
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