From: Dave Chinner <[email protected]>
To: Jens Axboe <[email protected]>
Cc: [email protected], [email protected]
Subject: Re: [PATCHSET for-next 0/3] Add FMODE_NOWAIT support to pipes
Date: Wed, 8 Mar 2023 17:46:48 +1100 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On Tue, Mar 07, 2023 at 08:33:24PM -0700, Jens Axboe wrote:
> On 3/7/23 8:10?PM, Jens Axboe wrote:
> > Curious on how big of a difference this makes, I wrote a small benchmark
> > that simply opens 128 pipes and then does 256 rounds of reading and
> > writing to them. This was run 10 times, discarding the first run as it's
> > always a bit slower. Before the patch:
> >
> > Avg: 262.52 msec
> > Stdev: 2.12 msec
> > Min: 261.07 msec
> > Max 267.91 msec
> >
> > and after the patch:
> >
> > Avg: 24.14 msec
> > Stdev: 9.61 msec
> > Min: 17.84 msec
> > Max: 43.75 msec
> >
> > or about a 10x improvement in performance (and efficiency).
>
> The above test was for a pipe being empty when the read is issued, if
> the test is changed to have data when, then it looks even better:
>
> Before:
>
> Avg: 249.24 msec
> Stdev: 0.20 msec
> Min: 248.96 msec
> Max: 249.53 msec
>
> After:
>
> Avg: 10.86 msec
> Stdev: 0.91 msec
> Min: 10.02 msec
> Max: 12.67 msec
>
> or about a 23x improvement.
Nice!
Code looks OK, maybe consider s/nonblock/nowait/, but I'm not a pipe
expert so I'll leave nitty gritty details to Al, et al.
Acked-by: Dave Chinner <[email protected]>
--
Dave Chinner
[email protected]
next prev parent reply other threads:[~2023-03-08 6:46 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-08 3:10 [PATCHSET for-next 0/3] Add FMODE_NOWAIT support to pipes Jens Axboe
2023-03-08 3:10 ` [PATCH 1/3] fs: add 'nonblock' parameter to pipe_buf_confirm() and fops method Jens Axboe
2023-03-14 9:11 ` Christian Brauner
2023-03-08 3:10 ` [PATCH 2/3] pipe: enable handling of IOCB_NOWAIT Jens Axboe
2023-03-14 9:26 ` Christian Brauner
2023-03-14 12:03 ` Jens Axboe
2023-03-14 9:38 ` Matthew Wilcox
2023-03-14 12:04 ` Jens Axboe
2023-03-08 3:10 ` [PATCH 3/3] pipe: set FMODE_NOWAIT on pipes Jens Axboe
2023-03-14 9:26 ` Christian Brauner
2023-03-08 3:33 ` [PATCHSET for-next 0/3] Add FMODE_NOWAIT support to pipes Jens Axboe
2023-03-08 6:46 ` Dave Chinner [this message]
2023-03-08 14:30 ` Jens Axboe
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