Re: [PATCH v2] f2fs: only flush the single temp bio cache which owns the target page

From: Jaegeuk Kim
Date: Mon Nov 12 2018 - 19:15:22 EST


On 10/24, Yunlong Song wrote:
> Previously, when f2fs finds which temp bio cache owns the target page,
> it will flush all the three temp bio caches, but we only need to flush
> one single bio cache indeed, which can help to keep bio merged.
>
> Signed-off-by: Yunlong Song <yunlong.song@xxxxxxxxxx>
> ---
> fs/f2fs/data.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 106f116..882e217 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -396,13 +396,17 @@ static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
> }
>
> static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi,
> - enum page_type type, enum temp_type temp)
> + struct inode *inode, struct page *page, nid_t ino,
> + enum page_type type, enum temp_type temp, bool force)
> {
> enum page_type btype = PAGE_TYPE_OF_BIO(type);
> struct f2fs_bio_info *io = sbi->write_io[btype] + temp;
>
> down_write(&io->io_rwsem);
>
> + if (!force && !__has_merged_page(io, inode, page, ino))
> + goto out;

Could you clean up this to call once in __submit_merged_write_cond() only?

> +
> /* change META to META_FLUSH in the checkpoint procedure */
> if (type >= META_FLUSH) {
> io->fio.type = META_FLUSH;
> @@ -412,6 +416,7 @@ static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi,
> io->fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
> }
> __submit_merged_bio(io);
> +out:
> up_write(&io->io_rwsem);
> }
>
> @@ -426,7 +431,7 @@ static void __submit_merged_write_cond(struct f2fs_sb_info *sbi,
>
> for (temp = HOT; temp < NR_TEMP_TYPE; temp++) {
>
> - __f2fs_submit_merged_write(sbi, type, temp);
> + __f2fs_submit_merged_write(sbi, inode, page, ino, type, temp, force);
>
> /* TODO: use HOT temp only for meta pages now. */
> if (type >= META)
> --
> 1.8.5.2