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From: Mike Galbraith <efault@gmx.de>
To: Jens Axboe <axboe@kernel.dk>, Paolo Valente <paolo.valente@linaro.org>
Cc: Christoph Hellwig <hch@lst.de>,
	linux-block <linux-block@vger.kernel.org>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Oleksandr Natalenko <oleksandr@natalenko.name>
Subject: Re: bug in tag handling in blk-mq?
Date: Wed, 09 May 2018 18:57:10 +0200	[thread overview]
Message-ID: <1525885030.15732.6.camel@gmx.de> (raw)
In-Reply-To: <ce5ee556-9552-6ffd-7578-7b3b983c07bf@kernel.dk>

On Wed, 2018-05-09 at 09:18 -0600, Jens Axboe wrote:
> On 5/8/18 10:11 PM, Mike Galbraith wrote:
> > On Tue, 2018-05-08 at 19:09 -0600, Jens Axboe wrote:
> >>
> >> Alright, I managed to reproduce it. What I think is happening is that
> >> BFQ is limiting the inflight case to something less than the wake
> >> batch for sbitmap, which can lead to stalls. I don't have time to test
> >> this tonight, but perhaps you can give it a go when you are back at it.
> >> If not, I'll try tomorrow morning.
> >>
> >> If this is the issue, I can turn it into a real patch. This is just to
> >> confirm that the issue goes away with the below.
> > 
> > Confirmed.  Impressive high speed bug stomping.
> 
> Well, that's good news. Can I get you to try this patch?

Sure thing.  The original hang (minus provocation patch) being
annoyingly non-deterministic, this will (hopefully) take a while.

	-Mike

  reply	other threads:[~2018-05-09 16:57 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-07 14:03 bug in tag handling in blk-mq? Paolo Valente
2018-05-07 16:39 ` Jens Axboe
2018-05-07 18:02   ` Paolo Valente
2018-05-08  4:51     ` Mike Galbraith
2018-05-08  8:37       ` Mike Galbraith
2018-05-08 14:55         ` Jens Axboe
2018-05-08 16:42           ` Mike Galbraith
2018-05-08 20:37             ` Jens Axboe
2018-05-08 21:19               ` Jens Axboe
2018-05-09  1:09                 ` Jens Axboe
2018-05-09  4:11                   ` Mike Galbraith
2018-05-09  5:06                     ` Paolo Valente
2018-05-09 15:18                     ` Jens Axboe
2018-05-09 16:57                       ` Mike Galbraith [this message]
2018-05-09 17:01                         ` Jens Axboe
2018-05-09 18:31                           ` Mike Galbraith
2018-05-09 19:50                             ` Jens Axboe
2018-05-10  4:38                               ` Mike Galbraith
2018-05-09  5:09               ` Mike Galbraith

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