From patchwork Thu Jan 10 03:19:25 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauricio Faria de Oliveira X-Patchwork-Id: 1022691 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 43Zrq72vvmz9sNt; Thu, 10 Jan 2019 14:20:35 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1ghQtQ-0000EP-NY; Thu, 10 Jan 2019 03:20:28 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.86_2) (envelope-from ) id 1ghQtJ-00008K-U6 for kernel-team@lists.ubuntu.com; Thu, 10 Jan 2019 03:20:21 +0000 Received: from mail-qt1-f197.google.com ([209.85.160.197]) by youngberry.canonical.com with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1ghQtJ-00013s-F3 for kernel-team@lists.ubuntu.com; Thu, 10 Jan 2019 03:20:21 +0000 Received: by mail-qt1-f197.google.com with SMTP id j5so8727311qtk.11 for ; Wed, 09 Jan 2019 19:20:21 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references; bh=gVTf4lvXp2UyhYUpcFIRslyNMW/NTp5RVrqj0eNIU7Q=; b=L05nyn8k08LkHeUP8UF2nnYeCOa+iYK4RvpMQo1vqwqLxqiEv+8QG1QpqMacnyqUW/ EtznIpjrUiK5Sc+zWeuNYFoLi45gAL58sJ0QCPeqrsiXfNf/4b2faoc4z13bdFQ/ksZH 1HdvJk9MKhlfdQ3DleAuUej1e8uSPg2yf4qxUFVgn2d9wfWos/tquIrK+6w15EUVmZYR tKfIz8PloRjPrO9Az+11GbPYyXiwGLZvJyRtdzETbQluAdvbhnypmbJ0Y6EOrYytFg+X 9cakIH94IYCdXlnOYYZRjjqWGQcA6wk9NoC50vNfRgNwDjsJAWQ+9c851MtkjvHxR/oE jZrw== X-Gm-Message-State: AJcUukdU65ZiPJk7MeH+SNekPDqeTbMbz5Z+uuw+miMZW5VyPpb8E3pO 6Z4H7LfQQ3v4gUZFqUvzd1wFRXMGrinUFcR1pS+sPXJ5JDmmRWutqR5aXyaC+3aeAP038zYdfOg qC/9FH3dtOOx4uAFXXOZIHElnN9IDPOP2xucM97I9yQ== X-Received: by 2002:a0c:da86:: with SMTP id z6mr8216321qvj.84.1547090420544; Wed, 09 Jan 2019 19:20:20 -0800 (PST) X-Google-Smtp-Source: ALg8bN6RjoKhpdDubn4ozgA+KAvpqXrs+FUFAeryKClUn9LhMJD9+4HBYtmuy2dlj/RAxPvFnRJ3Pg== X-Received: by 2002:a0c:da86:: with SMTP id z6mr8216315qvj.84.1547090420404; Wed, 09 Jan 2019 19:20:20 -0800 (PST) Received: from localhost.localdomain ([177.181.227.0]) by smtp.gmail.com with ESMTPSA id e129sm32371961qkf.85.2019.01.09.19.20.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 09 Jan 2019 19:20:20 -0800 (PST) From: Mauricio Faria de Oliveira To: kernel-team@lists.ubuntu.com Subject: [SRU C][PATCH 5/8] blk-wbt: fix has-sleeper queueing check Date: Thu, 10 Jan 2019 01:19:25 -0200 Message-Id: <20190110031928.30981-6-mfo@canonical.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190110031928.30981-1-mfo@canonical.com> References: <20190110031928.30981-1-mfo@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Jens Axboe BugLink: https://bugs.launchpad.net/bugs/1810998 We need to do this inside the loop as well, or we can allow new IO to supersede previous IO. Tested-by: Anchal Agarwal Signed-off-by: Jens Axboe (cherry picked from commit c45e6a037a536530bd25781ac7c989e52deb2a63) Signed-off-by: Mauricio Faria de Oliveira --- block/blk-wbt.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/block/blk-wbt.c b/block/blk-wbt.c index 53bd504471d2..9748a2fc684b 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -492,16 +492,17 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct, { struct rq_wait *rqw = get_rq_wait(rwb, wb_acct); DECLARE_WAITQUEUE(wait, current); + bool has_sleeper; - if (!wq_has_sleeper(&rqw->wait) && - rq_wait_inc_below(rqw, get_limit(rwb, rw))) + has_sleeper = wq_has_sleeper(&rqw->wait); + if (!has_sleeper && rq_wait_inc_below(rqw, get_limit(rwb, rw))) return; add_wait_queue_exclusive(&rqw->wait, &wait); do { set_current_state(TASK_UNINTERRUPTIBLE); - if (rq_wait_inc_below(rqw, get_limit(rwb, rw))) + if (!has_sleeper && rq_wait_inc_below(rqw, get_limit(rwb, rw))) break; if (lock) { @@ -510,6 +511,7 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct, spin_lock_irq(lock); } else io_schedule(); + has_sleeper = false; } while (1); __set_current_state(TASK_RUNNING);