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From: Dmitry Shulyak <[email protected]>
To: Jens Axboe <[email protected]>
Cc: [email protected]
Subject: Re: Very low write throughput on file opened with O_SYNC/O_DSYNC
Date: Wed, 19 Aug 2020 10:55:18 +0300	[thread overview]
Message-ID: <CAF-ewDrW-7hRuQ1QkNzJVbBWM5U4cTMi1reB=e=-dTuh8WymMg@mail.gmail.com> (raw)
In-Reply-To: <[email protected]>

reproducer with liburing -
https://github.com/dshulyak/liburing/blob/async-repro/test/async-repro.c
i am using self-written library in golang for interacting with uring,
but i can reproduce the same issue with that snippet consistently.

On Tue, 18 Aug 2020 at 19:42, Jens Axboe <[email protected]> wrote:
>
> On 8/18/20 9:09 AM, Dmitry Shulyak wrote:
> > it worked, but there are some issues.
> > with o_dsync and even moderate submission rate threads are stuck in
> > some cpu task (99.9% cpu consumption), and make very slow progress.
> > have you expected it? it must be something specific to uring, i can't
> > reproduce this condition by writing from 2048 threads.
>
> Do you have a reproducer I can run? Curious what that CPU spin is,
> that obviously shouldn't happen.
>
> --
> Jens Axboe
>

  reply	other threads:[~2020-08-19  7:55 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-17 11:46 Very low write throughput on file opened with O_SYNC/O_DSYNC Dmitry Shulyak
2020-08-17 11:58 ` Dmitry Shulyak
2020-08-17 14:29 ` Jens Axboe
2020-08-17 15:49   ` Dmitry Shulyak
2020-08-17 16:17     ` Jens Axboe
2020-08-18 16:09       ` Dmitry Shulyak
2020-08-18 16:42         ` Jens Axboe
2020-08-19  7:55           ` Dmitry Shulyak [this message]
2020-08-21 13:43             ` Dmitry Shulyak

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