From patchwork Mon Jun 25 15:12:30 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 10486661 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A9F1E6023A for ; Mon, 25 Jun 2018 15:18:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A6BCE2835B for ; Mon, 25 Jun 2018 15:18:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9BA182851D; Mon, 25 Jun 2018 15:18:14 +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=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable 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 3CF572835B for ; Mon, 25 Jun 2018 15:18:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934781AbeFYPRy (ORCPT ); Mon, 25 Jun 2018 11:17:54 -0400 Received: from mail-qt0-f195.google.com ([209.85.216.195]:41051 "EHLO mail-qt0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934760AbeFYPMt (ORCPT ); Mon, 25 Jun 2018 11:12:49 -0400 Received: by mail-qt0-f195.google.com with SMTP id y20-v6so12236640qto.8 for ; Mon, 25 Jun 2018 08:12:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=gkdJSYLh9LN7Ss8j0Rn9mX3g9Rqhn9vecXPFB0z5w9o=; b=EQF8Lm1v9iOrAGXShAs6yzFBe5UdR2PvSB5ZajUzmT2yXGXW6RIxpfYDkZ8sbBbZWB dLusYs55wJ6tR67k/i1gr2bkP6L4OHjWzgCWjkM6HxS9hVnEAapykK6ItuHlN3ty77cm 2yGzv47+qsZpEdubSwsdWO85l8EwTfgpi4um/eBhSMvlg2oE67JOiWRHfvVynpRUXM8P aOWRjRr0zAJhy0E1Aa1gcur39A9/s+S5MRdFSEf58Qj4M1iPim66567zCoFET45OlQE4 M8FJdD0iNpdS5yAFhigqoi71P4MBV/0WK/rmib4xl+dTwlsSneRfmZWvdWMrpNyL/jFo U7Tg== 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:in-reply-to :references; bh=gkdJSYLh9LN7Ss8j0Rn9mX3g9Rqhn9vecXPFB0z5w9o=; b=bzhZm7MdoGhm36Sgqu6mrDQdurQJeu6cNH9jBgmdfxqbYuJUPAKDp99D+HV5KWkbhz zO8pCU/WslDHcd/XnTRWDovXdJ/Fpgc2tMdtDJj6JDTRi5MnCO33ZtghAkp+n0vxAoTn 85ft2ieFtoGLbulNYl89mGF40vJRV9WrfqyhtliI83QL2V5C/U+HCQnkucQCTl+U8/QL naJX5XM6ru/rpp4JkyUTwkm984IgYtS2tR/mjrB5XnLCqJimj1VOO90K5PZV3Nm0nOlN 4SE3zNqaus9uSxMFj+QXJ1O/+BdcI+7XR97sywXNZKcMb8rhNC0BQuz2xN8vSo+1LYJo CIsw== X-Gm-Message-State: APt69E2FVf45rqcxv6ydIdL99i67f7Af//gyxFBzzAJJht74dYmY4wFS ZzNirynb0uqj5/shfsydCP+7Yw== X-Google-Smtp-Source: AAOMgpeSJa1CXpx5Yr9ZDKOghBCFPjbPBNf1GgMLrdwY8pFxLX/0JMb84yMStsej5Fe6subN6TaJlQ== X-Received: by 2002:aed:37c2:: with SMTP id j60-v6mr11330385qtb.417.1529939568954; Mon, 25 Jun 2018 08:12:48 -0700 (PDT) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id g49-v6sm10878806qtc.3.2018.06.25.08.12.48 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 25 Jun 2018 08:12:48 -0700 (PDT) From: Josef Bacik To: axboe@kernel.dk, linux-block@vger.kernel.org, kernel-team@fb.com, akpm@linux-foundation.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, tj@kernel.org, linux-fsdevel@vger.kernel.org Cc: Josef Bacik Subject: [PATCH 02/15] block: introduce bio_issue_as_root_blkg Date: Mon, 25 Jun 2018 11:12:30 -0400 Message-Id: <20180625151243.2132-3-josef@toxicpanda.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180625151243.2132-1-josef@toxicpanda.com> References: <20180625151243.2132-1-josef@toxicpanda.com> 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 From: Josef Bacik Instead of forcing all file systems to get the right context on their bio's, simply check for REQ_META to see if we need to issue as the root blkg. We don't want to force all bio's to have the root blkg associated with them if REQ_META is set, as some controllers (blk-iolatency) need to know who the originating cgroup is so it can backcharge them for the work they are doing. This helper will make sure that the controllers do the proper thing wrt the IO priority and backcharging. Signed-off-by: Josef Bacik Acked-by: Tejun Heo --- include/linux/blk-cgroup.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 6c666fd7de3c..69aa71dc0c04 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -238,6 +238,22 @@ static inline struct blkcg *bio_blkcg(struct bio *bio) return css_to_blkcg(task_css(current, io_cgrp_id)); } +/** + * bio_issue_as_root_blkg - see if this bio needs to be issued as root blkg + * @return: true if this bio needs to be submitted with the root blkg context. + * + * In order to avoid priority inversions we sometimes need to issue a bio as if + * it were attached to the root blkg, and then backcharge to the actual owning + * blkg. The idea is we do bio_blkcg() to look up the actual context for the + * bio and attach the appropriate blkg to the bio. Then we call this helper and + * if it is true run with the root blkg for that queue and then do any + * backcharging to the originating cgroup once the io is complete. + */ +static inline bool bio_issue_as_root_blkg(struct bio *bio) +{ + return (bio->bi_opf & REQ_META); +} + /** * blkcg_parent - get the parent of a blkcg * @blkcg: blkcg of interest