From nobody Sun Feb 8 12:14:46 2026 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 ECC45EB64D9 for ; Wed, 14 Jun 2023 09:20:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235394AbjFNJUT (ORCPT ); Wed, 14 Jun 2023 05:20:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243999AbjFNJT4 (ORCPT ); Wed, 14 Jun 2023 05:19:56 -0400 Received: from mx5.didiglobal.com (mx5.didiglobal.com [111.202.70.122]) by lindbergh.monkeyblade.net (Postfix) with SMTP id D9C3A10E9 for ; Wed, 14 Jun 2023 02:19:54 -0700 (PDT) Received: from mail.didiglobal.com (unknown [10.79.65.12]) by mx5.didiglobal.com (Maildata Gateway V2.8) with ESMTPS id 6A12DB012F056; Wed, 14 Jun 2023 17:19:52 +0800 (CST) Received: from didi-ThinkCentre-M930t-N000 (10.79.64.101) by ZJY02-ACTMBX-02.didichuxing.com (10.79.65.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Wed, 14 Jun 2023 17:19:51 +0800 Date: Wed, 14 Jun 2023 17:19:45 +0800 X-MD-Sfrom: tiozhang@didiglobal.com X-MD-SrcIP: 10.79.65.12 From: tiozhang To: , , , , CC: , , , , , , , , , , , Subject: [PATCH v2] sched/isolation: add a workqueue parameter to constrain unbound CPUs Message-ID: <20230614091923.GA1059@didi-ThinkCentre-M930t-N000> Mail-Followup-To: tj@kernel.org, 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@gmail.com, zyhtheonly@yeah.net MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230613092819.GA18487@didi-ThinkCentre-M930t-N000> User-Agent: Mutt/1.9.4 (2018-02-28) X-Originating-IP: [10.79.64.101] X-ClientProxiedBy: ZJY01-PUBMBX-01.didichuxing.com (10.79.64.32) To ZJY02-ACTMBX-02.didichuxing.com (10.79.65.12) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Motivation of doing this is to better improve boot times for devices when we want to prevent our workqueue works from running on some specific CPUs, e,g, some CPUs are busy with interrupts. Suggested-by: Tejun Heo Signed-off-by: tiozhang --- kernel/sched/isolation.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index 373d42c707bc..5cd67c51622e 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -181,8 +181,8 @@ static int __init housekeeping_nohz_full_setup(char *st= r) { unsigned long flags; =20 - 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_MISC + | HK_FLAG_KTHREAD; =20 return housekeeping_setup(str, flags); } @@ -208,6 +208,12 @@ static int __init housekeeping_isolcpus_setup(char *st= r) continue; } =20 + if (!strncmp(str, "workqueue,", 10)) { + str +=3D 10; + flags |=3D HK_FLAG_WQ; + continue; + } + if (!strncmp(str, "managed_irq,", 12)) { str +=3D 12; flags |=3D HK_FLAG_MANAGED_IRQ; --=20 2.17.1