Re: [PATCH 2/4] block: avoid to merge splitted bio

From	Jeff Moyer <jmoyer@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 2/4] block: avoid to merge splitted bio
Date	2015-10-15 17:20 +0200
Message-ID	<qjStX-1O0-3@gated-at.bofh.it> (permalink)
References	<qjl50-2Ud-5@gated-at.bofh.it> <qjl50-2Ud-21@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Ming Lei <ming.lei@canonical.com> writes:

> The splitted bio has been already too fat to merge, so mark it
> as NOMERGE.
>
> Signed-off-by: Ming Lei <ming.lei@canonical.com>

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>

> ---
>  block/blk-merge.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/block/blk-merge.c b/block/blk-merge.c
> index 22293fd..de5716d8 100644
> --- a/block/blk-merge.c
> +++ b/block/blk-merge.c
> @@ -139,6 +139,9 @@ void blk_queue_split(struct request_queue *q, struct bio **bio,
>  	bio_set_flag(res, BIO_SEG_VALID);
>  
>  	if (split) {
> +		/* there isn't chance to merge the splitted bio */
> +		split->bi_rw |= REQ_NOMERGE;
> +
>  		bio_chain(split, *bio);
>  		generic_make_request(*bio);
>  		*bio = split;
--
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[PATCH 0/4] block: some misc changes Ming Lei <ming.lei@canonical.com> - 2015-10-14 05:40 +0200
  [PATCH 1/4] block: setup bi_phys_segments after splitting Ming Lei <ming.lei@canonical.com> - 2015-10-14 05:40 +0200
    Re: [PATCH 1/4] block: setup bi_phys_segments after splitting Jeff Moyer <jmoyer@redhat.com> - 2015-10-15 17:20 +0200
  [PATCH 3/4] blk-mq: check bio_mergeable() early before merging Ming Lei <ming.lei@canonical.com> - 2015-10-14 05:40 +0200
    Re: [PATCH 3/4] blk-mq: check bio_mergeable() early before merging Jeff Moyer <jmoyer@redhat.com> - 2015-10-15 17:30 +0200
      Re: [PATCH 3/4] blk-mq: check bio_mergeable() early before merging Ming Lei <ming.lei@canonical.com> - 2015-10-16 02:30 +0200
  [PATCH 4/4] blk-mq: mark ctx as pending at batch in flush plug path Ming Lei <ming.lei@canonical.com> - 2015-10-14 05:40 +0200
    Re: [PATCH 4/4] blk-mq: mark ctx as pending at batch in flush plug path Jeff Moyer <jmoyer@redhat.com> - 2015-10-15 17:30 +0200
      Re: [PATCH 4/4] blk-mq: mark ctx as pending at batch in flush plug path Ming Lei <ming.lei@canonical.com> - 2015-10-16 02:30 +0200
  [PATCH 2/4] block: avoid to merge splitted bio Ming Lei <ming.lei@canonical.com> - 2015-10-14 05:40 +0200
    Re: [PATCH 2/4] block: avoid to merge splitted bio Jeff Moyer <jmoyer@redhat.com> - 2015-10-15 17:20 +0200

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