From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from vulcan.natalenko.name ([104.207.131.136]:24328 "EHLO vulcan.natalenko.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966930AbeBNJzo (ORCPT ); Wed, 14 Feb 2018 04:55:44 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 14 Feb 2018 10:55:41 +0100 From: Oleksandr Natalenko To: Paolo Valente Cc: Mike Galbraith , Jens Axboe , stable Subject: Re: [PATCH BUGFIX V3] block, bfq: add requeue-request hook In-Reply-To: <07DA441B-C2E8-4F65-B674-11C87D2F084B@linaro.org> References: <20180207211920.6343-1-paolo.valente@linaro.org> <1518197379.26824.31.camel@gmx.de> <6394471.U0O273vb9H@natalenko.name> <9E24F648-C93A-4CEA-A1B6-B041540CEAAE@linaro.org> <1518434553.13087.7.camel@gmx.de> <805e9d5af9aed3fbc2697fdb0ce51e88@natalenko.name> <1518498175.6944.48.camel@gmx.de> <816E0B1B-B2D9-4604-A8CB-1E32AFBF6C22@linaro.org> <1518504174.6944.71.camel@gmx.de> <1518504640.6944.73.camel@gmx.de> <1518532236.15792.25.camel@gmx.de> <1518587910.5647.14.camel@gmx.de> <1518591888.6752.12.camel@gmx.de> <1518592512.6752.14.camel@gmx.de> <07DA441B-C2E8-4F65-B674-11C87D2F084B@linaro.org> Message-ID: <30107c3d7cc4dadb0d6949b7dd30d565@natalenko.name> Sender: stable-owner@vger.kernel.org List-ID: Hi. 14.02.2018 09:56, Paolo Valente wrote: > This has evidently to do with tag pressure. I've looked for a way to > easily reduce the number of tags online, so as to put your system in > the bad spot deterministically. But at no avail. Does anyone know a > way to do it? Isn't this a case for block device queue_depth? IIRC, the amount of tags is derived from it. Oleksandr