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 B63D9EB64D8 for ; Thu, 22 Jun 2023 03:47:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229881AbjFVDrX (ORCPT ); Wed, 21 Jun 2023 23:47:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53900 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229513AbjFVDrU (ORCPT ); Wed, 21 Jun 2023 23:47:20 -0400 Received: from mail-oo1-xc2e.google.com (mail-oo1-xc2e.google.com [IPv6:2607:f8b0:4864:20::c2e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E73941BCA for ; Wed, 21 Jun 2023 20:47:18 -0700 (PDT) Received: by mail-oo1-xc2e.google.com with SMTP id 006d021491bc7-55e1a9ff9d4so138602eaf.1 for ; Wed, 21 Jun 2023 20:47:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687405638; x=1689997638; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=QrQ4pMlhuN5RPf831t214Aq/9pqMzT3UkPKa92aAjMU=; b=k1S9Qlx6DpdFXPkJhL80whZ0sFKSR2kRpj2C0YRXbCrpgmCvy68gybu3it8XW+Ma8y L9gHhFAI8GZHevsY89WyeWqnXNBCkhj3P7T+ch8khHLFwNNPs2e/BiesTHlFMTLmoQeY gJKOB3NOMxt2N0DKxQE65xiAfTgNDe13KulJrMIA8Zd9nOm4BXqoBqPLujKTU7q6Pao6 Aow6HoCAJZh1DKiqY+vl98H51GlgR1r92Eg20+8Mm1yeDyKB9GYV/KF5NYWd0fXRM8Lv neB19PWKMLihXn5z4RDvgaElXXydyOLQquYnBwNbjRq3j+Ujy3TqV9+GqIIajuV9J0Z/ rnkQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687405638; x=1689997638; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=QrQ4pMlhuN5RPf831t214Aq/9pqMzT3UkPKa92aAjMU=; b=jAlEt5BXRrgQBZK8MRezrmuGOFeJ2iEBFMjfSPKTUC5nohbVZFyUACko/5K7hJe46c 0EigNXs1DpvKOG7ziX2OQKznC73GVZNjiAxePGY51C/RANA1b7xqfau12P79F+jKfl5q 4kA5fDfaiawqvrBhong+DOGzmkyOkSE0LB+cNg5HIVkR3Vce7xVO++pqSlYh2/ahg1or khHmpQxX0bJcWk5NU7UIuBfvo3J5FxmtODEczv3rsfjwWjBMpPjULPwl7Q+CEd8vuxoV FLbnIbejAD1mQ/NPgTqi37sP/p6X3wsUdMytL1IG7utmE96ZGApaU6smJ7Q9YnbP8qNN mZfg== X-Gm-Message-State: AC+VfDz1G2nS3Jg08JW5bVJ/p9pIo3c8ExCbA0KkOX9KxDGup4Eg0pDn W4IkY7ZC+vupNjAFG0a+wPy+cYmo9oQJuOmJUgg= X-Google-Smtp-Source: ACHHUZ4+K75TjqDX9BQbQ/AyA2GIGg3XeRAXOWQnTvTvtdydKRJACsXbVoYlF/kRsIx7qECQ7weoVTg2PgyDKCOFWCA= X-Received: by 2002:aca:3288:0:b0:3a0:30c9:8281 with SMTP id y130-20020aca3288000000b003a030c98281mr4849897oiy.16.1687405638113; Wed, 21 Jun 2023 20:47:18 -0700 (PDT) MIME-Version: 1.0 References: <20230613092819.GA18487@didi-ThinkCentre-M930t-N000> <20230614091923.GA1059@didi-ThinkCentre-M930t-N000> In-Reply-To: From: Yuanhan Zhang Date: Thu, 22 Jun 2023 11:47:06 +0800 Message-ID: Subject: Re: [PATCH v2] sched/isolation: add a workqueue parameter to constrain unbound CPUs To: Tejun Heo Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.co, vincent.guittot@linaro.org, linux-kernel@vger.kernel.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, fuyuanli@didiglobal.com, zwp10758@gmail.com, zyhtheonly@yeah.net Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tejun Heo =E4=BA=8E2023=E5=B9=B46=E6=9C=8822=E6=97=A5=E5=91= =A8=E5=9B=9B 04:51=E5=86=99=E9=81=93=EF=BC=9A > > On Wed, Jun 14, 2023 at 05:19:45PM +0800, tiozhang wrote: > ... > > @@ -181,8 +181,8 @@ static int __init housekeeping_nohz_full_setup(char= *str) > > { > > unsigned long flags; > > > > - flags =3D HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU= | > > - HK_FLAG_MISC | HK_FLAG_KTHREAD; > > + flags =3D HK_FLAG_TICK | HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MI= SC > > + | HK_FLAG_KTHREAD; > > Why is WQ being taken out of nohz_full setup? The patch description doesn= 't > mention anything. To prevent nohz_full from rewriting workqueue's choice. Add a description in patch v3. > > > @@ -208,6 +208,12 @@ static int __init housekeeping_isolcpus_setup(char= *str) > > continue; > > } > > > > + if (!strncmp(str, "workqueue,", 10)) { > > + str +=3D 10; > > + flags |=3D HK_FLAG_WQ; > > + continue; > > + } > > I wonder whether it'd be better to just add a workqueue boot param but if I also write a patch this way, please see '[PATCH] workqueue: add cmdline parameter `unbound_workqueue_cpus` to further constrain wq_unbound_cpumask at boot ti= me'. If you think it is better I'm happy to continue on this :) > this works it's fine too. It works since we use this cpumask to constrain wq_unbound_cpumask in workqueue's early init. > > Thanks. > > -- > tejun Thank you, tiozhang