From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Daniel Smedegaard Buus <danielbuus@gmail.com>
Cc: Kent Overstreet <kmo@daterainc.com>,
Sam Fulcomer <enotty@brown.edu>,
Francis Moreau <francis.moro@gmail.com>,
Daniel J Blueman <daniel@quora.org>,
linux-bcache@vger.kernel.org
Subject: Re: [PATCH] bcache: fix writeback thread to sleep less intrusively
Date: Wed, 30 Apr 2014 10:24:55 -0700 [thread overview]
Message-ID: <20140430172455.GA3029@birch.djwong.org> (raw)
In-Reply-To: <CAHnuAewaE5r0Z9L+EL93SscrrYsFphnrWCD4Vb32O8VjX2PK+w@mail.gmail.com>
On Wed, Apr 30, 2014 at 01:51:14PM +0200, Daniel Smedegaard Buus wrote:
> Hi :)
>
> What's the state of this?
>
> I have this issue on a number of EC2 instances that are using bcache
> to speed up EBS access by caching on the ephemeral SSDs (writethrough
> mode).
>
> "echo 0 > /sys/block/bcache0/bcache/writeback_running" as suggested by
> others stops the flood of "blocked" messages in dmesg, but it only
> partly fixes the 2.0 minimum load average issue (instead, it's now a
> 1.0 minimum load average).
I haven't spent time on figuring out the other source of load average. Kent
didn't seem to like the patch to convert the bcache_writeback thread to
interruptible sleep (I recall he said it was 'wrong', but didn't elaborate).
--D
>
> I just tried the latest kernel I could get my hands on for Ubuntu
> Trusty, the mainline v3.15-rc2 (built April 20th), and it exhibits the
> same behavior.
>
> Thanks :)
>
> Daniel
next prev parent reply other threads:[~2014-04-30 17:25 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-11 0:26 [PATCH] bcache: fix writeback thread to sleep less intrusively Darrick J. Wong
2014-04-11 0:46 ` Kent Overstreet
2014-04-11 1:41 ` Darrick J. Wong
2014-04-12 2:31 ` Darrick J. Wong
2014-04-12 2:33 ` [PATCH] bcache: let the writeback thread run at least once at startup Darrick J. Wong
2014-04-30 11:51 ` [PATCH] bcache: fix writeback thread to sleep less intrusively Daniel Smedegaard Buus
2014-04-30 17:24 ` Darrick J. Wong [this message]
2014-05-01 9:38 ` Daniel Smedegaard Buus
2014-05-01 21:54 ` Slava Pestov
2014-05-20 7:07 ` Daniel J Blueman
[not found] ` <CACHGV4+mNu_KV7JazT-34D++3S2NKhDkOmc_wo0QfrfdqpccoQ@mail.gmail.com>
2014-07-09 10:27 ` Daniel Smedegaard Buus
2014-07-09 15:53 ` Peter Kieser
2014-07-09 18:02 ` Daniel Smedegaard Buus
2014-07-09 18:19 ` Slava Pestov
2014-07-09 19:18 ` Daniel Smedegaard Buus
2014-04-11 7:26 ` Francis Moreau
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