From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754717AbeARIZt (ORCPT ); Thu, 18 Jan 2018 03:25:49 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:35936 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750972AbeARIZr (ORCPT ); Thu, 18 Jan 2018 03:25:47 -0500 X-Google-Smtp-Source: ACJfBosXGE1AtPVLfWGDRbh5pvC2CSxYHSt8u+mDBGcuxgw0S6cNOmlLZX8Q932L8qQsrxNUEMvIpA== Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.2 \(3445.5.20\)) Subject: Re: [PATCH BUGFIX/IMPROVEMENT 0/2] block, bfq: two pending patches From: Paolo Valente In-Reply-To: <20180113110518.2519-1-paolo.valente@linaro.org> Date: Thu, 18 Jan 2018 09:25:43 +0100 Cc: linux-block , linux-kernel@vger.kernel.org, ulf.hansson@linaro.org, broonie@kernel.org, linus.walleij@linaro.org, bfq-iosched@googlegroups.com, oleksandr@natalenko.name Message-Id: <8EB4BACE-3D6D-4EB7-844E-45092AC7644B@linaro.org> References: <20180113110518.2519-1-paolo.valente@linaro.org> To: Jens Axboe X-Mailer: Apple Mail (2.3445.5.20) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id w0I8Prc4005315 > Il giorno 13 gen 2018, alle ore 12:05, Paolo Valente ha scritto: > > Hi Jens, > here are again the two pending patches you asked me to resend [1]. One > of them, fixing read-starvation problems, was accompanied by a cover > letter. I'm pasting the content of that cover letter below. > > The patch addresses (serious) starvation problems caused by > request-tag exhaustion, as explained in more detail in the commit > message. I started from the solution in the function > kyber_limit_depth, but then I had to define more articulate limits, to > counter starvation also in cases not covered in kyber_limit_depth. > If this solution proves to be effective, I'm willing to port it > somehow to the other schedulers. > Hi Jens, have had to time to check these patches? Sorry for pushing, but I guess 4.16 is getting closer, and these patches are performance critical; especially the first, which solves a starvation problem. Thanks, Paolo > Thanks, > Paolo > > [1] https://www.spinics.net/lists/linux-block/msg21586.html > > Paolo Valente (2): > block, bfq: limit tags for writes and async I/O > block, bfq: limit sectors served with interactive weight raising > > block/bfq-iosched.c | 158 +++++++++++++++++++++++++++++++++++++++++++++++++--- > block/bfq-iosched.h | 17 ++++++ > block/bfq-wf2q.c | 3 + > 3 files changed, 169 insertions(+), 9 deletions(-) > > -- > 2.15.1