From c718379b6b0954a04a153d7e5dc8b3136a301ee6 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Wed, 24 Apr 2013 13:19:56 +0900 Subject: f2fs: give a chance to merge IOs by IO scheduler Previously, background GC submits many 4KB read requests to load victim blocks and/or its (i)node blocks. ... f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb61, blkaddr = 0x3b964ed f2fs_gc : block_rq_complete: 8,16 R () 499854968 + 8 [0] f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb6f, blkaddr = 0x3b964ee f2fs_gc : block_rq_complete: 8,16 R () 499854976 + 8 [0] f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb79, blkaddr = 0x3b964ef f2fs_gc : block_rq_complete: 8,16 R () 499854984 + 8 [0] ... However, by the fact that many IOs are sequential, we can give a chance to merge the IOs by IO scheduler. In order to do that, let's use blk_plug. ... f2fs_gc : f2fs_iget: ino = 143 f2fs_gc : f2fs_readpage: ino = 143, page_index = 0x1c6, blkaddr = 0x2e6ee f2fs_gc : f2fs_iget: ino = 143 f2fs_gc : f2fs_readpage: ino = 143, page_index = 0x1c7, blkaddr = 0x2e6ef : block_rq_complete: 8,16 R () 1519616 + 8 [0] : block_rq_complete: 8,16 R () 1519848 + 8 [0] : block_rq_complete: 8,16 R () 1520432 + 96 [0] : block_rq_complete: 8,16 R () 1520536 + 104 [0] : block_rq_complete: 8,16 R () 1521008 + 112 [0] : block_rq_complete: 8,16 R () 1521440 + 152 [0] : block_rq_complete: 8,16 R () 1521688 + 144 [0] : block_rq_complete: 8,16 R () 1522128 + 192 [0] : block_rq_complete: 8,16 R () 1523256 + 328 [0] ... Note that this issue should be addressed in checkpoint, and some readahead flows too. Reviewed-by: Namjae Jeon Signed-off-by: Jaegeuk Kim --- fs/f2fs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/f2fs/file.c') diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 0e56db2d3cc9..9dfcdab5ea7c 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -212,7 +212,7 @@ static void truncate_partial_data_page(struct inode *inode, u64 from) if (!offset) return; - page = find_data_page(inode, from >> PAGE_CACHE_SHIFT); + page = find_data_page(inode, from >> PAGE_CACHE_SHIFT, false); if (IS_ERR(page)) return; -- cgit v1.2.3