From: Jens Axboe <axboe@kernel.dk>
To: Ming Lei <tom.leiming@gmail.com>, linux-kernel@vger.kernel.org
Cc: Mike Snitzer <snitzer@redhat.com>, Tejun Heo <tj@kernel.org>
Subject: Re: [PATCH 0/4] block: account io: kill atomic operations
Date: Thu, 16 Jul 2015 08:48:41 -0600 [thread overview]
Message-ID: <55A7C449.4030406@kernel.dk> (raw)
In-Reply-To: <1437016607-375-1-git-send-email-tom.leiming@gmail.com>
On 07/15/2015 09:16 PM, Ming Lei wrote:
> Hi,
>
> This patches kills two kinds of atomic operations in block
> accounting I/O.
>
> The 1st two patches convert atomic refcount of partition
> into percpu refcount.
>
> The 2nd two patches converts partition->in_flight[] into percpu
> variable.
>
> With this change, ~15% throughput improvement can be observed
> when running fio(randread) over null blk in a dual-socket
> environment.
I've played with this before, but always ran into the hurdle of making
part_in_flight() too expensive ended up hurting results in the end.
Making the inc/dec parts of accounting percpu is a no-brainer,
unfortunately the summing then becomes pretty expensive. I'll run this
through some testing and see what kind of results I get.
--
Jens Axboe
next prev parent reply other threads:[~2015-07-16 14:48 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-16 3:16 [PATCH 0/4] block: account io: kill atomic operations Ming Lei
2015-07-16 3:16 ` [PATCH 1/4] block: partition: introduce hd_free_part() Ming Lei
2015-07-16 3:16 ` [PATCH 2/4] block: partition: convert percpu ref Ming Lei
2015-07-16 14:36 ` Tejun Heo
2015-07-16 3:16 ` [PATCH 3/4] block: partition: introduce 'cpu' para to part_inc|dec_in_flight Ming Lei
2015-07-16 3:16 ` [PATCH 4/4] block: account io: convert part->in_fligh[] into percpu variable Ming Lei
2015-07-16 14:40 ` Tejun Heo
2015-07-16 14:48 ` Jens Axboe [this message]
2015-07-16 14:59 ` [PATCH 0/4] block: account io: kill atomic operations Tejun Heo
2015-07-16 15:02 ` Jens Axboe
2015-07-16 15:01 ` Ming Lei
2015-07-16 15:09 ` Jens Axboe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=55A7C449.4030406@kernel.dk \
--to=axboe@kernel.dk \
--cc=linux-kernel@vger.kernel.org \
--cc=snitzer@redhat.com \
--cc=tj@kernel.org \
--cc=tom.leiming@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox