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From: Dave Chinner <david@fromorbit.com>
To: Joshi <joshiiitr@gmail.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: Strange behavior with log IO fake-completions
Date: Wed, 26 Sep 2018 10:59:35 +1000	[thread overview]
Message-ID: <20180926005935.GC31060@dastard> (raw)
In-Reply-To: <CA+1E3rL1JA1PWC+53aU+RQcxFucccXu7M-K-m9AiEXaCjfCF=w@mail.gmail.com>

On Mon, Sep 24, 2018 at 07:55:02PM +0530, Joshi wrote:
> > I changed all log wait queues (ic_force_wait, ic_write_wait, and
> xc_commit_wait) into completion variables (despite knowing that it is
> also implemented using wait_queue).
> 
> Sorry, ignore this and subsequent part of the text. I think replacing
> with completion requires more work than I did.Calling "complete_all"
> is tricky, given the need of calling "reinit_completion" which may get
> executed by multiple threads in this case.

Yup.

Perhaps 
you might like to look at this recent patch set aimed at reducing
spurious wake-ups and lock contention in the log reservation code:

https://marc.info/?l=linux-kernel&m=153531683127094&w=2

Not sure it applies to this case, but it still may be useful to you.

BTW, when posting benchmark results, can you also include a baseline
result from a completely unmodified kernel and the patches you are
testing? Nobody can evaluate the correctness or effectiveness of the
changes you are testing without these things....

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

      reply	other threads:[~2018-09-26  7:10 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-10 18:07 Strange behavior with log IO fake-completions Joshi
2018-09-10 23:58 ` Dave Chinner
2018-09-11  4:10   ` Joshi
2018-09-12  0:42     ` Dave Chinner
2018-09-14 11:51       ` Joshi
2018-09-17  2:56         ` Dave Chinner
2018-09-21  0:23           ` Dave Chinner
2018-09-21 12:54             ` Joshi
2018-09-24 14:25               ` Joshi
2018-09-26  0:59                 ` Dave Chinner [this message]

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