• Jaegeuk Kim's avatar
    f2fs: add a sysfs entry to control max_victim_search · b1c57c1c
    Jaegeuk Kim authored
    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: default avatarJaegeuk Kim <jaegeuk.kim@samsung.com>
    b1c57c1c
super.c 28.5 KB