f2fs: select target segment with closer temperature in SSR mode
authorChao Yu <yuchao0@huawei.com>
Fri, 24 Feb 2017 10:46:00 +0000 (18:46 +0800)
committerJaegeuk Kim <jaegeuk@kernel.org>
Mon, 27 Feb 2017 17:59:56 +0000 (09:59 -0800)
In SSR mode, we can allocate target segment which has different
temperature type from the type of current block, in order to avoid
mixing coldest and hottest data/node as much as possible, change
SSR allocation policy to select closer temperature for current
block prior.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
fs/f2fs/segment.c

index 1bab09097590a030e047befa3b018517e8515cf8..9006d8ed6f525a69ecf8149d06443558e1384eca 100644 (file)
@@ -1541,7 +1541,8 @@ static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
 {
        struct curseg_info *curseg = CURSEG_I(sbi, type);
        const struct victim_selection *v_ops = DIRTY_I(sbi)->v_ops;
-       int i, n;
+       int i, cnt;
+       bool reversed = false;
 
        /* need_SSR() already forces to do this */
        if (v_ops->get_victim(sbi, &(curseg)->next_segno, BG_GC, type, SSR))
@@ -1549,14 +1550,24 @@ static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
 
        /* For node segments, let's do SSR more intensively */
        if (IS_NODESEG(type)) {
-               i = CURSEG_HOT_NODE;
-               n = CURSEG_COLD_NODE;
+               if (type >= CURSEG_WARM_NODE) {
+                       reversed = true;
+                       i = CURSEG_COLD_NODE;
+               } else {
+                       i = CURSEG_HOT_NODE;
+               }
+               cnt = NR_CURSEG_NODE_TYPE;
        } else {
-               i = CURSEG_HOT_DATA;
-               n = CURSEG_COLD_DATA;
+               if (type >= CURSEG_WARM_DATA) {
+                       reversed = true;
+                       i = CURSEG_COLD_DATA;
+               } else {
+                       i = CURSEG_HOT_DATA;
+               }
+               cnt = NR_CURSEG_DATA_TYPE;
        }
 
-       for (; i <= n; i++) {
+       for (; cnt-- > 0; reversed ? i-- : i++) {
                if (i == type)
                        continue;
                if (v_ops->get_victim(sbi, &(curseg)->next_segno,