All of lore.kernel.org
 help / color / mirror / Atom feed
From: Song Liu <song@kernel.org>
To: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Cc: linux-raid <linux-raid@vger.kernel.org>
Subject: Re: [PATCH] md: improve io stats accounting
Date: Tue, 2 Jun 2020 10:16:23 -0700	[thread overview]
Message-ID: <CAPhsuW6JNjnGQg6BARGGzb+ohOrcLKaTvs4bAm60NzAwQ-svpw@mail.gmail.com> (raw)
In-Reply-To: <26d5f5c7-9a20-e7f9-617f-0353c5d9bb2e@intel.com>

On Tue, Jun 2, 2020 at 4:47 AM Artur Paszkiewicz
<artur.paszkiewicz@intel.com> wrote:
>
> On 6/2/20 8:48 AM, Song Liu wrote:
> >> +               clone = bio_clone_fast(bio, GFP_NOIO, &mddev->md_io_bs);
> >
> > Handle clone == NULL?
>
> I think this should never fail - bio_alloc_bioset() guarantees that. It
> is used in a similar manner in raid1 and raid10. How about
> BUG_ON(clone == NULL)?

I misread the code. Current version is fine.

>
> > Also, have you done benchmarks with this change?
>
> I tested 4k random reads on a raid0 (4x P4510 2TB) and it was 2550k vs
> 2567k IOPS, that's slower only by about 0.66%:

Thanks for the test. I will do some more tests and process the patch
after the merge
window.

Song

  reply	other threads:[~2020-06-02 17:16 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-01 16:12 [PATCH] md: improve io stats accounting Artur Paszkiewicz
2020-06-01 22:03 ` kbuild test robot
2020-06-01 22:03   ` kbuild test robot
2020-06-02  6:22   ` Song Liu
2020-06-02  6:22     ` Song Liu
2020-06-02  6:31     ` [kbuild-all] " Rong Chen
2020-06-02  6:31       ` Rong Chen
2020-06-02  6:48 ` Song Liu
2020-06-02 11:47   ` Artur Paszkiewicz
2020-06-02 17:16     ` Song Liu [this message]
2020-06-02 17:32     ` John Stoffel
2020-06-02  7:01 ` kbuild test robot
2020-06-02  7:01   ` kbuild test robot
2020-06-08 14:37 ` Guoqing Jiang
2020-07-02  6:30   ` Song Liu

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=CAPhsuW6JNjnGQg6BARGGzb+ohOrcLKaTvs4bAm60NzAwQ-svpw@mail.gmail.com \
    --to=song@kernel.org \
    --cc=artur.paszkiewicz@intel.com \
    --cc=linux-raid@vger.kernel.org \
    /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.