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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.