From patchwork Fri Jun 29 19:25:30 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 10497419 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 0AD1F60325 for ; Fri, 29 Jun 2018 19:29:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F0F7C29754 for ; Fri, 29 Jun 2018 19:29:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E58D9298F9; Fri, 29 Jun 2018 19:29:44 +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 9387329754 for ; Fri, 29 Jun 2018 19:29:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936952AbeF2T3l (ORCPT ); Fri, 29 Jun 2018 15:29:41 -0400 Received: from mail-qt0-f193.google.com ([209.85.216.193]:42290 "EHLO mail-qt0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934248AbeF2TZs (ORCPT ); Fri, 29 Jun 2018 15:25:48 -0400 Received: by mail-qt0-f193.google.com with SMTP id y31-v6so8829749qty.9 for ; Fri, 29 Jun 2018 12:25:48 -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=lvUbPMbc+sZ/5s4o0FACiGm2SVguhyOZvDPVCUu5DqDNjS4hp0cxAu4OsI4dVpAXIt fY37AGYKv7uKaxUx97B+1hXrDDahup3fJutWuVVH6y3stcdiBAYW9We7mUsrtpmsbW8L HvKYDOysSQrsavvzeTjJG+2wiVFaJQ7ArTCuBV9qxJ4F4hP5rYEOMLuldCei5w8A2hZK vxVLebXBPrRwStAq1HVI02th/m845ixb6kdu0NjCeDsK8Htbmz5RdgGRLcclvadwOCx7 8ETyL6hfiXCd2PhcOoYvYh62U/o90IQjEPTDt4Ck92o2aI3iL+RHIlEYFM7InYimU1OI rI/g== 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=m0k84cOLJVdZ7F/mqecWUbFHS7NXAv+IjgYOS3HD0LvhZjluIpi1kisY87a298JB0Q /WVt4RTAWYzQfQNOIvRv5hlJwotVOp1bFZs8Z4GY+9KopaCCzTd4wkYmsNnXmIYNkTai 6xWusXVD3mP2cIstqHx4zBLZ6YLdlRD6e5It3b1EJpGdu869VCH33lbe8uEO7FR75EJC 9J3Y5IAJpTM0ZLdoFmWHZ3OzfE699rghn6jpyfvHSMu+TioVTPyc2lz1XvssdkglC7i/ jhkZFhG/T/StQZAOM+KL+XHojSeQRZP3Nv+Ld3IyPcYB9iNxdA/Z2YBDYqAUqvfO0Czh 6GuA== X-Gm-Message-State: APt69E0CO8spUwOE63AkSwpT8TgV5iLvUwheI2ndlVi6FvaQvdf3FYPo Yf38qC7cQSEY5jclkqEQHMxjhNz/zrw= X-Google-Smtp-Source: AAOMgpeXS1VimVQQ8ne/1t0hLtrU8zIG9LCTGJnXcImtSUHkYd3LJN/R+aRpIe5P6lvLhFKSIYhdxA== X-Received: by 2002:ac8:317b:: with SMTP id h56-v6mr15316109qtb.191.1530300347945; Fri, 29 Jun 2018 12:25:47 -0700 (PDT) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id d192-v6sm7178406qkb.46.2018.06.29.12.25.47 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 29 Jun 2018 12:25:47 -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, tj@kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: Josef Bacik Subject: [PATCH 02/14] block: introduce bio_issue_as_root_blkg Date: Fri, 29 Jun 2018 15:25:30 -0400 Message-Id: <20180629192542.26649-3-josef@toxicpanda.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180629192542.26649-1-josef@toxicpanda.com> References: <20180629192542.26649-1-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