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>

1 files changed, 5 insertions, 0 deletions

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index b161db4a96a4..d94acbc3d928 100644
--- 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);