From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 579F1C43465 for ; Fri, 18 Sep 2020 00:45:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 07BF620838 for ; Fri, 18 Sep 2020 00:45:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600389902; bh=RDiNbKKGW8G1pZpUOrU2qELYa3bbrS/9vkl36Jx/dmc=; h=From:To:Cc:Subject:Date:List-ID:From; b=QAUMPfwcEzyuNiI5MWMTVVFDFJcXUy5W8Z/f/5AOQVMK4vIhuWgcV1WHzWVmVY06J J8vN3k3O+hSVBZsQ8sFqfbetLeFKCZNmJfAcmlfI34i9g3F3o+z+adH895YEU+qiMY qvAG73uXJvDNlNrL0xd42WKHBMsvYEiupftlQOLc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726200AbgIRApB (ORCPT ); Thu, 17 Sep 2020 20:45:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726007AbgIRApA (ORCPT ); Thu, 17 Sep 2020 20:45:00 -0400 Received: from mail-qv1-xf42.google.com (mail-qv1-xf42.google.com [IPv6:2607:f8b0:4864:20::f42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1B3FC06174A; Thu, 17 Sep 2020 17:45:00 -0700 (PDT) Received: by mail-qv1-xf42.google.com with SMTP id cv8so1999846qvb.12; Thu, 17 Sep 2020 17:45:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=I4g8oZaM4I1PTgkVQKRiJNIBO3rGE09QsJ8U+iD020Q=; b=oqR+7x5dJyQcBEwZDtu1PVnUg0zlf4DCuy1Zp8tZ2FigjcnKMuj2pg78JL2AbnBQLM lpNqq/FRqu/ytyo8P0ug/B0NXdeHsnftsBfGkIM6w01ef/dTfOFlrd8uvz0wYDofxW2j XG2W1jvJ1QCpUQjZYlT3L7Y/KLFvXTba2Foj+z6KNYngQWofDOXSMuS9OfxiwO+OkcXo ngQeOqW5OMDzeAazkPzJ+x3uqMA5U3+dI26Nu8OaD8VY+C0DSbIWFjjQuaQDxENVb17v W8e68mbdDldx+0xBYRKbuIFe5WVgXpXmEniOLKGUU2XkHCRJE3SDflzZRT653J+gyPdT yMGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; bh=I4g8oZaM4I1PTgkVQKRiJNIBO3rGE09QsJ8U+iD020Q=; b=fij2JfqxIU0h0hqxh6f/kLhTL6TkLLCjJ6pOdO4ucbSi4EEOJVdFep57EYqYDpwp+q ApvMaY536ZVJYnzJIooW8ucKQNm+VAtm86WEUGoz+W5+uPyAdGyp6AbPMdJ3pyDk1sqe gL7ddc08sPloEkNYfKjI2UJoR/rw4OqkfPF5KYx+g2rMidN/E739a2KOEN/e/orWDCGy QpD2YkuEPlwydHc198Py5lhgSbynDL42UYDYUPEBFDg5cB98b/9IBtLlA8EOegVm3cH8 /jiwncANM8VYcbAXtZxqdOWYJmkeDtq9QKgPGPuyTSIzduIFeM3DR35njjKBdB06GPkx D/Fw== X-Gm-Message-State: AOAM531FvIYP3qK4FJ6SXQKZFMSt4/oPl/nuD7c4q1slT4zf4MOHkPAR ca0CA1SBz2OqHq63TC2OZnBHtQNtLCeJiQ== X-Google-Smtp-Source: ABdhPJyn2pmKBLJDKQFFGWpimDyrVIFq6Efh5yAXczEBVLkltpvJg6VKFJcu0xaZIpkehLhIddMH3Q== X-Received: by 2002:ad4:4594:: with SMTP id x20mr31706024qvu.4.1600389899750; Thu, 17 Sep 2020 17:44:59 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:6893]) by smtp.gmail.com with ESMTPSA id v131sm1064791qkb.15.2020.09.17.17.44.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Sep 2020 17:44:59 -0700 (PDT) From: Tejun Heo To: axboe@kernel.dk Cc: linux-block@vger.kernel.org, cgroups@vger.kernel.org, kernel-team@fb.com, linux-kernel@vger.kernel.org Subject: [PATCHSET for-5.10/block] iocost: improve debt forgiveness logic Date: Thu, 17 Sep 2020 20:44:51 -0400 Message-Id: <20200918004456.593983-1-tj@kernel.org> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Debt reduction logic was recently added by dda1315f1853 ("blk-iocost: halve debts if device stays idle"). While it was effective at avoiding pathological cases where some iocgs were kept delayed while the device was most idle, it wasn't very effective at addressing more complex conditions and could leave low priority cgroups unnecessarily harshly throttled under moderate load. This patchset improves the debt forgiveness logic so that it's more effective at reducing such unnecessary throttling. This patchset contains the following five patches: 0001-iocost-factor-out-ioc_forgive_debts.patch 0002-iocost-replace-nr_shortages-cond-in-ioc_forgive_debt.patch 0003-iocost-recalculate-delay-after-debt-reduction.patch 0004-iocost-reimplement-debt-forgiveness-using-average-us.patch 0005-iocost-add-iocg_forgive_debt-tracepoint.patch and is also available in the following git tree: git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git iocost-debt-forgiveness diffstat follows. Thanks. block/blk-iocost.c | 141 +++++++++++++++++++++++++++++------------- include/trace/events/iocost.h | 41 ++++++++++++ 2 files changed, 141 insertions(+), 41 deletions(-) -- tejun