From patchwork Thu Aug 16 16:51:14 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Valente X-Patchwork-Id: 10567871 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6F407913 for ; Thu, 16 Aug 2018 16:52:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5CA812B3EA for ; Thu, 16 Aug 2018 16:52:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4F5E12B47F; Thu, 16 Aug 2018 16:52:01 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 03C082B48E for ; Thu, 16 Aug 2018 16:52:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730187AbeHPTvg (ORCPT ); Thu, 16 Aug 2018 15:51:36 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:45250 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727247AbeHPTvf (ORCPT ); Thu, 16 Aug 2018 15:51:35 -0400 Received: by mail-wr1-f66.google.com with SMTP id f12-v6so4736485wrv.12 for ; Thu, 16 Aug 2018 09:51:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id; bh=kAJN5fxC24ZODwvl+eKV5x4mhAs5Fw7VBfu8pF7El8s=; b=fGHLAMAMm2lu4C8wbEa9LebpuT0CWFBu8Dl2kK/eZX0j4PU7yubwoMjcXb2/l76E68 url8VIG0TUwC7auEYiMr006uz+2nxGfKfIOTQL9YYHzLD3VnfZsvw17xw+NjiPY41s1o XaiDFv07Bb2iWxRqI2up33sXAQZF8mvSVmgpQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=kAJN5fxC24ZODwvl+eKV5x4mhAs5Fw7VBfu8pF7El8s=; b=Ak0P3//d67t58/ZfwvX54kS2E0rpxl6cbJL2fhyrAqL/UkJiR45wWGP0SHtEGXI+Xo fk+G/xo3iW4rdO9Gj2JBERS+7SQAbjxtL2BZ1Qqq7H5Jja1lyLv61mDmYPEorR2n5iHV eHPdpMKpzpC0AVEv7NNHxr4yePzIeMGI1oJjk5O/QvYv/WkF1gVqNjjC3ZyGSKBLkILI V9D0sgJUPeYuZK+zCzAfsYsoSLRiEvnMqUAhDEp8+xChkvyE3evtRpXU5BsUvhwibHMy dHhGXMXkSvuXGIj+fEtflSQxC7UCYi8PnrDah3dgCNtebWtlTYT3eMapmAIsBWS4SwBW FxKw== X-Gm-Message-State: AOUpUlGlVR43gsHU0Hx1uFrsPOiQgW81L29uVA+UaPRR+f7Jm1pVqKKO a2uhwQVqcO0dp7vjT2r0zJ1lcw== X-Google-Smtp-Source: AA+uWPwrIXEOxfwHQ1ScvvFjEAlbdtaxTUZ6ObwN+omTBKgZLK8CpHMh2nF5cbOoqF8dyCzzROSWsQ== X-Received: by 2002:adf:f1c8:: with SMTP id z8-v6mr2412002wro.214.1534438315762; Thu, 16 Aug 2018 09:51:55 -0700 (PDT) Received: from localhost.localdomain (146-241-5-103.dyn.eolo.it. [146.241.5.103]) by smtp.gmail.com with ESMTPSA id o3-v6sm30036180wrj.31.2018.08.16.09.51.54 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 16 Aug 2018 09:51:55 -0700 (PDT) From: Paolo Valente To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, ulf.hansson@linaro.org, linus.walleij@linaro.org, broonie@kernel.org, bfq-iosched@googlegroups.com, oleksandr@natalenko.name, Paolo Valente Subject: [PATCH BUGFIX/IMPROVEMENT 0/4] bfq: two fixes and one improvement related to I/O control Date: Thu, 16 Aug 2018 18:51:14 +0200 Message-Id: <20180816165118.17402-1-paolo.valente@linaro.org> X-Mailer: git-send-email 2.16.1 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hi Jens, while working a little bit on cgroups I/O control, I found two nasty bugs in bfq. They break bandwidth control in simple configurations with one-process groups. These bugs are fixed by the first two patches in this series. These fixes improved I/O control so much, that I could reduce the write overcharge factor, used by bfq to counter write-induced issues. This reduction is performed by the third patch. The fourth patch contains a little code improvement I made in a function that has to do with I/O control. I hope we are still in time for 4.19. Thanks, Paolo Paolo Valente (4): block, bfq: readd missing reset of parent-entity service block, bfq: always update the budget of an entity when needed block, bfq: reduce write overcharge block, bfq: improve code of bfq_bfqq_charge_time block/bfq-iosched.c | 54 +++++++++++++++++++++++++++++++++++++++-------------- block/bfq-wf2q.c | 22 +++++++++++----------- 2 files changed, 51 insertions(+), 25 deletions(-) --- 2.16.1