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
next prev parent reply other threads:[~2020-06-02 17:16 UTC|newest]
Thread overview: 11+ 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
2020-06-02 6:22 ` Song Liu
2020-06-02 6:31 ` [kbuild-all] " 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
2020-06-08 14:37 ` Guoqing Jiang
2020-07-02 6:30 ` Song Liu
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