Re: [PATCH 3/8] dm: pass 'dm_io' instance to dm_io_acct directly

Mike Snitzer
2022-04-12T20:42:15Z

On Tue, Apr 12 2022 at 4:56P -0400,
Ming Lei <ming.lei@redhat.com> wrote:

> All the other 4 parameters are retrieved from the 'dm_io' instance, so
> not necessary to pass all four to dm_io_acct().
>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>

Yeah, commit 0ab30b4079e103 ("dm: eliminate copying of dm_io fields in
dm_io_dec_pending") could've gone further to do what you've done here
in this patch.

But it stopped short because of the additional "games" associated with
the late assignment of io->orig_bio that is in the dm-5.19 branch.

Mike

> ---
> drivers/md/dm.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/md/dm.c b/drivers/md/dm.c
> index 62f7af815ef8..ed85cd1165a4 100644
> --- a/drivers/md/dm.c
> +++ b/drivers/md/dm.c
> @@ -498,9 +498,12 @@ static bool bio_is_flush_with_data(struct bio *bio)
> return ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size);
> }
>
> -static void dm_io_acct(bool end, struct mapped_device *md, struct bio *bio,
> - unsigned long start_time, struct dm_stats_aux *stats_aux)
> +static void dm_io_acct(struct dm_io *io, bool end)
> {
> + struct dm_stats_aux *stats_aux = &io->stats_aux;
> + unsigned long start_time = io->start_time;
> + struct mapped_device *md = io->md;
> + struct bio *bio = io->orig_bio;
> bool is_flush_with_data;
> unsigned int bi_size;
>
> @@ -528,7 +531,7 @@ static void dm_io_acct(bool end, struct mapped_device *md, struct bio *bio,
>
> static void __dm_start_io_acct(struct dm_io *io)
> {
> - dm_io_acct(false, io->md, io->orig_bio, io->start_time, &io->stats_aux);
> + dm_io_acct(io, false);
> }
>
> static void dm_start_io_acct(struct dm_io *io, struct bio *clone)
> @@ -557,7 +560,7 @@ static void dm_start_io_acct(struct dm_io *io, struct bio *clone)
>
> static void dm_end_io_acct(struct dm_io *io)
> {
> - dm_io_acct(true, io->md, io->orig_bio, io->start_time, &io->stats_aux);
> + dm_io_acct(io, true);
> }
>
> static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio)
> --
> 2.31.1
>
> --
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