From patchwork Tue Jun 5 13:29:37 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 10448227 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 0B2106024A for ; Tue, 5 Jun 2018 13:29:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EBDE929365 for ; Tue, 5 Jun 2018 13:29:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DF83E29374; Tue, 5 Jun 2018 13:29:58 +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=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 8627929365 for ; Tue, 5 Jun 2018 13:29:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751965AbeFEN3z (ORCPT ); Tue, 5 Jun 2018 09:29:55 -0400 Received: from mail-qk0-f193.google.com ([209.85.220.193]:38867 "EHLO mail-qk0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751937AbeFEN3y (ORCPT ); Tue, 5 Jun 2018 09:29:54 -0400 Received: by mail-qk0-f193.google.com with SMTP id y4-v6so1469334qka.5 for ; Tue, 05 Jun 2018 06:29:53 -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=g/aypdOHZxY0xlgmHhuhe0N2q2D6PHEZVM71ZhH3IECmNYDpGhMw1pK6yhvLD5E/Cr bm3+GVvFec3xrJvJ76ZBz6NvSqlGPxAWyXfXeohpSsZ3lAsmOTlHS54M3RPVV2sZb4kt r8Ov7KQxWoKUVkZ8tGH/Y6WSBP0F+iI92HhxZDQAw2w4K+J945c3FDzc2ZsMN7SrxPzL 0FWXJqEID2h1gAgyXfNO3oHI3sHmaBkph6waG45JGbWBwYJb6XOy7koWhGQWC/OQZJWJ AXmzIwL2Y7SC0jbdaN+MSBn26URGfIckJZ3hAq/Hi1z02lnhrRaAkXAV6ovu52ZgJNzt tmqA== 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=EsyQVaSBqlnr1RQijcGw86r3xpg2l1bmG020TGzREWpAWgLiCXGsK//mjopUJJ87JB Rq1h0S1PehbKSVOmPvXgQcUstZpQeFcnlxol1oZS3OSr3F3YBbT4fn7vmp4Jed5uVuJK 9gOfImenDZYNjntHApf6Jey8FbMNott/KyP0qCobDK7qxZUH4wzoquSdm14DroY1yURF zifQSgIejJE/rs8EdQNG87X+0t5HktQOFee7o/u2BkoRsilao8o53Cc/Fxda+3zBldfU FhdCcvbyUJgCKWPqipa2AU6xFJF5+kjElD9pf2NZESJIEkVol5VK/ZorQ8d2b2ANCHrA ii/A== X-Gm-Message-State: APt69E3yHphkyarcuPkSsBB6UV/Dla8ur/SAJSKFk07SGReiLLYv4tC2 vTF9qwUEzCITfuscrvewSFa6fg== X-Google-Smtp-Source: ADUXVKJxzeq4laEnJ31hb0Alq20thTOACtbPLhrZ8BwZz2HJvXZcQ/kaO2ihRN5Yxmiy77FSkHjl8w== X-Received: by 2002:a37:c551:: with SMTP id p78-v6mr22895053qki.184.1528205393572; Tue, 05 Jun 2018 06:29:53 -0700 (PDT) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id t184-v6sm35297617qkc.6.2018.06.05.06.29.52 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 05 Jun 2018 06:29:53 -0700 (PDT) From: Josef Bacik To: axboe@kernel.dk, kernel-team@fb.com, linux-block@vger.kernel.org, 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 02/13] block: introduce bio_issue_as_root_blkg Date: Tue, 5 Jun 2018 09:29:37 -0400 Message-Id: <20180605132948.1664-3-josef@toxicpanda.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180605132948.1664-1-josef@toxicpanda.com> References: <20180605132948.1664-1-josef@toxicpanda.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@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