From: Shaohua Li <shli@kernel.org>
To: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: [PATCH] raid10: improve random reads performance
Date: Tue, 19 Jul 2016 15:20:06 -0700 [thread overview]
Message-ID: <20160719222006.GA79792@kernel.org> (raw)
In-Reply-To: <1466770816-5227-1-git-send-email-tomasz.majchrzak@intel.com>
On Fri, Jun 24, 2016 at 02:20:16PM +0200, Tomasz Majchrzak wrote:
> RAID10 random read performance is lower than expected due to excessive spinlock
> utilisation which is required mostly for rebuild/resync. Simplify allow_barrier
> as it's in IO path and encounters a lot of unnecessary congestion.
>
> As lower_barrier just takes a lock in order to decrement a counter, convert
> counter (nr_pending) into atomic variable and remove the spin lock. There is
> also a congestion for wake_up (it uses lock internally) so call it only when
> it's really needed. As wake_up is not called constantly anymore, ensure process
> waiting to raise a barrier is notified when there are no more waiting IOs.
>
> Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Patch looks good, applied. Do you have data how this improves the performance?
Thanks,
Shaohua
next prev parent reply other threads:[~2016-07-19 22:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-24 12:20 [PATCH] raid10: improve random reads performance Tomasz Majchrzak
2016-07-19 22:20 ` Shaohua Li [this message]
2016-07-20 7:31 ` Tomasz Majchrzak
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=20160719222006.GA79792@kernel.org \
--to=shli@kernel.org \
--cc=linux-raid@vger.kernel.org \
--cc=tomasz.majchrzak@intel.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.