From: Hannes Reinecke <hare@suse.de>
To: Ming Lei <ming.lei@redhat.com>, Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org,
Jeffle Xu <jefflexu@linux.alibaba.com>,
Mike Snitzer <snitzer@redhat.com>,
dm-devel@redhat.com, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH V6 02/12] block: define 'struct bvec_iter' as packed
Date: Thu, 22 Apr 2021 15:18:24 +0200 [thread overview]
Message-ID: <2ae12dc1-804f-59f9-6837-3508d6176804@suse.de> (raw)
In-Reply-To: <20210422122038.2192933-3-ming.lei@redhat.com>
On 4/22/21 2:20 PM, Ming Lei wrote:
> 'struct bvec_iter' is embedded into 'struct bio', define it as packed
> so that we can get one extra 4bytes for other uses without expanding
> bio.
>
> 'struct bvec_iter' is often allocated on stack, so making it packed
> doesn't affect performance. Also I have run io_uring on both
> nvme/null_blk, and not observe performance effect in this way.
>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
> include/linux/bvec.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/bvec.h b/include/linux/bvec.h
> index ff832e698efb..a0c4f41dfc83 100644
> --- a/include/linux/bvec.h
> +++ b/include/linux/bvec.h
> @@ -43,7 +43,7 @@ struct bvec_iter {
>
> unsigned int bi_bvec_done; /* number of bytes completed in
> current bvec */
> -};
> +} __packed;
>
> struct bvec_iter_all {
> struct bio_vec bv;
>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@suse.de +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
next prev parent reply other threads:[~2021-04-22 13:18 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-22 12:20 [PATCH V6 00/12] block: support bio based io polling Ming Lei
2021-04-22 12:20 ` [PATCH V6 01/12] block: add helper of blk_queue_poll Ming Lei
2021-04-22 12:20 ` [PATCH V6 02/12] block: define 'struct bvec_iter' as packed Ming Lei
2021-04-22 13:18 ` Hannes Reinecke [this message]
2021-04-22 12:20 ` [PATCH V6 03/12] block: add one helper to free io_context Ming Lei
2021-04-22 12:20 ` [PATCH V6 04/12] block: move block polling code into one dedicated source file Ming Lei
2021-04-22 13:19 ` Hannes Reinecke
2021-04-26 7:12 ` Hannes Reinecke
2021-04-22 12:20 ` [PATCH V6 05/12] block: extract one helper function polling hw queue Ming Lei
2021-04-22 12:20 ` [PATCH V6 06/12] block: prepare for supporting bio_list via other link Ming Lei
2021-04-22 12:20 ` [PATCH V6 07/12] block: create io poll context for submission and poll task Ming Lei
2021-04-22 12:20 ` [PATCH V6 08/12] block: add req flag of REQ_POLL_CTX Ming Lei
2021-04-22 12:20 ` [PATCH V6 09/12] block: use per-task poll context to implement bio based io polling Ming Lei
2021-04-26 7:17 ` Hannes Reinecke
2021-04-22 12:20 ` [PATCH V6 10/12] block: limit hw queues to be polled in each blk_poll() Ming Lei
2021-04-26 7:19 ` Hannes Reinecke
2021-04-26 8:00 ` Ming Lei
2021-04-26 9:05 ` Hannes Reinecke
2021-04-22 12:20 ` [PATCH V6 11/12] block: allow to control FLAG_POLL via sysfs for bio poll capable queue Ming Lei
2021-04-26 7:20 ` Hannes Reinecke
2021-04-22 12:20 ` [PATCH V6 12/12] dm: support IO polling for bio-based dm device Ming Lei
2021-04-23 1:32 ` JeffleXu
2021-04-23 2:39 ` Ming Lei
2021-04-23 2:38 ` [PATCH V7 " Ming Lei
2021-05-17 6:16 ` [PATCH V6 00/12] block: support bio based io polling JeffleXu
2021-05-17 7:13 ` Ming Lei
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