f2fs: delay awaking discard thread

It's better to delay awaking discard thread while queuing discard commands
in checkpoint, it will help to give more chances for merging big and small
discard.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 45da59b72035023ab8e9a98551f878f1f0070c0a..b27ae5f6a87f1f2ee857f1026dbdaa9738c11013 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -968,7 +968,6 @@ static int __queue_discard_cmd(struct f2fs_sb_info *sbi,
                blkstart -= FDEV(devi).start_blk;
        }
        __update_discard_tree_range(sbi, bdev, lblkstart, blkstart, blklen);
-       wake_up(&SM_I(sbi)->dcc_info->discard_wait_queue);
        return 0;
 }
 
@@ -1335,6 +1334,8 @@ skip:
                SM_I(sbi)->dcc_info->nr_discards -= total_len;
                kmem_cache_free(discard_entry_slab, entry);
        }
+
+       wake_up(&SM_I(sbi)->dcc_info->discard_wait_queue);
 }
 
 static int create_discard_cmd_control(struct f2fs_sb_info *sbi)