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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97429C433EF for ; Tue, 15 Mar 2022 01:15:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344211AbiCOBQS (ORCPT ); Mon, 14 Mar 2022 21:16:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344204AbiCOBQS (ORCPT ); Mon, 14 Mar 2022 21:16:18 -0400 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D1D5E3464D for ; Mon, 14 Mar 2022 18:15:07 -0700 (PDT) Received: by mail-pl1-x62f.google.com with SMTP id u2so27280ple.10 for ; Mon, 14 Mar 2022 18:15:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=from:to:cc:in-reply-to:references:subject:message-id:date :mime-version:content-transfer-encoding; bh=YYXrSkA7DcKX+OZWoRaWmcezxkTTC0s3clPNsqj0tSs=; b=zf7n+VLD+TlQXBul0FjxSYL20r03zWROyOA5y4hxMFq+RWaP03LQynIiq5YiSKbkkk 4FokEd9K2SBXzY3lcpBYaxnM/XggXqkIcGAl5r05eOeLMuqueQt1qHpL0y8ONY4UkRWB nBOQR2g1Id/IcgIVc7vZwbInbJNmzdP7pfzuyCm25Qt9oioTkTV7badO8iz5bBmcssLB 0KIgZROVlTgkXqbEl5+PXmSTXM8mvNynBnTBPRurvJ4XazuIINdwhDb2y8z6I8b9DvMa CFUppDDNwXn58Mk4IdX6/z8JxMriMX7GpU4cFu1j/62+ZYdkJ1XGn6qd4uA2m29bS33j 5CfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:in-reply-to:references:subject :message-id:date:mime-version:content-transfer-encoding; bh=YYXrSkA7DcKX+OZWoRaWmcezxkTTC0s3clPNsqj0tSs=; b=tRIe4+OCva4erPf63XaTlQ7BOf+bi2rYLevGoDMdSTSzn6JZG5odHEPW1n9MA9nTLG f8t1rxlwYMt9b46Qvw3ax9tpPh7orQ59aV15SKkZm3UE/FajEifNjw4EfxzDJxFvgzCn HoCXgqImlIdQ2MZW6XPrQIo5VcWqQkYgLOLyxePda8v9nBIVvhgeWMluqh1Ry06boid8 xmLFmy8otOclmaXXzgg757ikKTeYdOjf4QuQkET9pmvsdLxCVdyZCH1LIAsjVmaVZUL3 XmmLFzQZ2AucPJnMf5apdHdLMpdIfcAxJsOQAgMo6h5FWB0q740d4TZ7J5b0MK31SK14 Uzyw== X-Gm-Message-State: AOAM533W+EfCKH2kHDBGFnLiIf7p3AcjdSRBg1LerBPT7hlE+Z7xDW6J n5LYcXpG1p7bOnxXei/YD+r50Q== X-Google-Smtp-Source: ABdhPJybZTuIVdsdqiq9XXOjoE5OhuzK9g5Qb+orkGS7bDm7/WhD/PUXavEFFaj8efC60jR46TlAXQ== X-Received: by 2002:a17:90a:1f4d:b0:1bb:a657:ace5 with SMTP id y13-20020a17090a1f4d00b001bba657ace5mr1830551pjy.39.1647306907272; Mon, 14 Mar 2022 18:15:07 -0700 (PDT) Received: from [127.0.1.1] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id k6-20020a17090a7f0600b001c63352cadbsm510847pjl.29.2022.03.14.18.15.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Mar 2022 18:15:06 -0700 (PDT) From: Jens Axboe To: Tejun Heo Cc: Josef Bacik , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, kernel-team@fb.com In-Reply-To: References: Subject: Re: [PATCH v3 for-5.18/block] block: don't merge across cgroup boundaries if blkcg is enabled Message-Id: <164730690621.219116.11184082869298025827.b4-ty@kernel.dk> Date: Mon, 14 Mar 2022 19:15:06 -0600 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, 14 Mar 2022 14:30:11 -1000, Tejun Heo wrote: > blk-iocost and iolatency are cgroup aware rq-qos policies but they didn't > disable merges across different cgroups. This obviously can lead to > accounting and control errors but more importantly to priority inversions - > e.g. an IO which belongs to a higher priority cgroup or IO class may end up > getting throttled incorrectly because it gets merged to an IO issued from a > low priority cgroup. > > [...] Applied, thanks! [1/1] block: don't merge across cgroup boundaries if blkcg is enabled commit: 6b2b04590b51aa4cf395fcd185ce439cab5961dc Best regards, -- Jens Axboe