On 2017/5/11 10:41, Jaegeuk Kim wrote: > On 05/11, Chao Yu wrote: >> Hi Jaegeuk, >> >> On 2017/5/11 7:48, Jaegeuk Kim wrote: >>> This patch avoids to use f2fs_submit_merged_bio for read, which was the only >>> read case. >> >> This makes f2fs losing the chance to merge multiple pages into one bio during >> reading continuous physical blocks, it may cause potential performance >> regression, how about using a local bio in ra_meta_pages to cache more pages? > > This is a readahead flow, which is asynchronous and not a performance critical > flow. And, I expect blk_plug is still able to merge them. We're using this in > readahead of node blocks as well. Confirmed, block plug can do the merge. :) Thanks, > > Thanks, > >> >> Thanks, >> >>> >>> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> >>> --- >>> fs/f2fs/checkpoint.c | 4 +--- >>> 1 file changed, 1 insertion(+), 3 deletions(-) >>> >>> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c >>> index ea9c317b5916..8d92f8249000 100644 >>> --- a/fs/f2fs/checkpoint.c >>> +++ b/fs/f2fs/checkpoint.c >>> @@ -207,12 +207,10 @@ int ra_meta_pages(struct f2fs_sb_info *sbi, block_t start, int nrpages, >>> } >>> >>> fio.page = page; >>> - fio.old_blkaddr = fio.new_blkaddr; >>> - f2fs_submit_page_mbio(&fio); >>> + f2fs_submit_page_bio(&fio); >>> f2fs_put_page(page, 0); >>> } >>> out: >>> - f2fs_submit_merged_bio(sbi, META, READ); >>> blk_finish_plug(&plug); >>> return blkno - start; >>> } >>> > > . >
