f2fs: readahead contiguous SSA blocks for f2fs_gc

If there are multi segments in one section, we will read those SSA blocks which
have contiguous address one by one in f2fs_gc. It may lost performance, let's
read ahead SSA blocks by merge multi read request.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 757b77b..c8516ee 100644 (file)
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -82,6 +82,7 @@ inline int get_max_meta_blks(struct f2fs_sb_info *sbi, int type)
                return NM_I(sbi)->max_nid / NAT_ENTRY_PER_BLOCK;
        case META_SIT:
                return SIT_BLK_CNT(sbi);
+       case META_SSA:
        case META_CP:
                return 0;
        default:
@@ -90,7 +91,7 @@ inline int get_max_meta_blks(struct f2fs_sb_info *sbi, int type)
 }
 
 /*
- * Readahead CP/NAT/SIT pages
+ * Readahead CP/NAT/SIT/SSA pages
  */
 int ra_meta_pages(struct f2fs_sb_info *sbi, int start, int nrpages, int type)
 {
@@ -125,8 +126,9 @@ int ra_meta_pages(struct f2fs_sb_info *sbi, int start, int nrpages, int type)
                                goto out;
                        prev_blk_addr = blk_addr;
                        break;
+               case META_SSA:
                case META_CP:
-                       /* get cp block addr */
+                       /* get ssa/cp block addr */
                        blk_addr = blkno;
                        break;
                default:

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 6f88191..bd6666e 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -89,12 +89,13 @@ enum {
 };
 
 /*
- * For CP/NAT/SIT readahead
+ * For CP/NAT/SIT/SSA readahead
  */
 enum {
        META_CP,
        META_NAT,
-       META_SIT
+       META_SIT,
+       META_SSA
 };
 
 /* for the list of orphan inodes */

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index b161db4..d94acbc 100644 (file)
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -708,6 +708,11 @@ gc_more:
                goto stop;
        ret = 0;
 
+       /* readahead multi ssa blocks those have contiguous address */
+       if (sbi->segs_per_sec > 1)
+               ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), sbi->segs_per_sec,
+                                                               META_SSA);
+
        for (i = 0; i < sbi->segs_per_sec; i++)
                do_garbage_collect(sbi, segno + i, &ilist, gc_type);