From mboxrd@z Thu Jan 1 00:00:00 1970 From: Francis Moreau Subject: Re: [PATCH] bcache: fix uninterruptible sleep in writeback thread Date: Mon, 02 Jun 2014 16:07:53 +0200 Message-ID: <538C8539.1060607@gmail.com> References: <1398981150-27765-1-git-send-email-sp@daterainc.com> <537112A5.6040709@kieser.ca> <53747499.3070000@gmail.com> <5374F9D2.8020209@kernel.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wg0-f45.google.com ([74.125.82.45]:43053 "EHLO mail-wg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754438AbaFBOGP (ORCPT ); Mon, 2 Jun 2014 10:06:15 -0400 Received: by mail-wg0-f45.google.com with SMTP id m15so5098696wgh.4 for ; Mon, 02 Jun 2014 07:06:13 -0700 (PDT) In-Reply-To: <5374F9D2.8020209@kernel.dk> Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Jens Axboe Cc: Peter Kieser , kmo@daterainc.com, linux-bcache@vger.kernel.org Hello, On 05/15/2014 07:30 PM, Jens Axboe wrote: > On 05/15/2014 02:02 AM, Francis Moreau wrote: >> Hello Jens, >> >> On 05/12/2014 08:27 PM, Peter Kieser wrote: >>> >>> On 2014-05-05 3:30 PM, Nikolay Amiantov wrote: >>>> 2014-05-02 1:52 GMT+04:00 Slava Pestov : >>>>> There were two issues here: >>>>> >>>>> - writeback thread did not start until the device first became dirty >>>>> - writeback thread used uninterruptible sleep once running >>>>> >>>>> Without this patch I see kernel warnings printed and a load average of >>>>> 1.52 after booting my test VM. With this patch the warnings are gone and >>>>> the load average is near 0.00 as expected. >>>> I've tried this patch and it has indeed fixed [1]! Thanks! >>>> >>>> [1]: https://bugzilla.kernel.org/show_bug.cgi?id=69471 >>> >>> Kent, >>> >>> Could you please review this patch, and have it pushed upstream? >>> >> >> Would it be possible to merge this patch directly before 3.15 is being >> released since kent don't seem to care about bugs in bcache or maybe he >> does but very selectively ? >> >> Also it would be great that stable trees will be fixed. >> >> Eventually I would suggest to mark bcache as an experimental thing since >> it's really not ready for production, just take a look at the bcache >> mailing list to see why. At least people won't be disappointed when >> they'll use bcache and see ton of koops. > > I'd really like to get Kent to weigh in on this. Sometimes it appears > straightforward to switch from uninterruptible to interruptible sleep, > but then signals get in the way. > Any progress ? Thanks.