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 230E3C4167B for ; Tue, 28 Nov 2023 16:56:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345027AbjK1Q4I (ORCPT ); Tue, 28 Nov 2023 11:56:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32952 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234908AbjK1Q4F (ORCPT ); Tue, 28 Nov 2023 11:56:05 -0500 Received: from mail-pf1-x42b.google.com (mail-pf1-x42b.google.com [IPv6:2607:f8b0:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8152810DF; Tue, 28 Nov 2023 08:56:10 -0800 (PST) Received: by mail-pf1-x42b.google.com with SMTP id d2e1a72fcca58-6cbe68095a3so4377898b3a.3; Tue, 28 Nov 2023 08:56:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1701190570; x=1701795370; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=z9nMu2b9XnNdD7wwpc++nEgEZUAhRsWBPvFZ/Lzv9fU=; b=Lo4QXgCvx2WCiRB8oO6oxd3mjwdJW7Qj69j9JAJ4ldMooqv9h4PDFoSNj91Yx5DGqZ O4qFChXx/gU7fFlT5uQhBit77Biv+YGjYDTKk28nambdWyirKPlaTtzqm57T8Iq4pWOp wtzr1fHQBfHvTcrHhYBMHDOfyDo4RFKezw5mlZvzpT45JUbZOTzhJq/tXvO0KCcVguj8 Jgx/8Ld0i75T6SpTSr0r+KoleJdps/9J/Fox8g0t4rvYOHysZxMyAFYTMXdGPsHM2+4M FWPGBi2KRs2s0Hsf9RaCORB+5C5QEFZkRqKSwWO2GnGBxC3tu6ltLBpkGyZ63Y0+Dmmg 0AjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701190570; x=1701795370; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=z9nMu2b9XnNdD7wwpc++nEgEZUAhRsWBPvFZ/Lzv9fU=; b=UK2Svwi/7VtHoU0H8LKiG7O7FwiXPEFemZp5IkcbowSHW5Hvn0R1agbQAZLPQFS6XO hw9WZQimZfqBt2AanauY7zL1U/7vQT5awjPsOA5yZBPYfGMpFifgm/fhM1rBmchQ0DUs xLTRTlMMPHbIPc81XcJXjF/GMpp4fN/HB412jmmvlwiNwuvHNh7dh9rSA+5cBd2raeYZ QYL/gORjFqESwDnUyQxFfBmEAid0Vxi0gNrKIX89XfNjlaZl4Wvwio73Ax9ApK6QjsI0 qLZS2zY+uv7+cGvY91kfmO7ykrxZIbniXw1qP8CT0kqvAtZ7zYAAvUdt46VqJY5AD2Te iJEA== X-Gm-Message-State: AOJu0Yz9RWUesLIvGzmcUWNf4QgK316qYBDKP/6rmWi+e8MNwdbs3q8W FwcXAFsmECDsCMtYIYi5mZs= X-Google-Smtp-Source: AGHT+IECbePOLzsM4J0Ktx1r5sk5ABhCCoNJdirIjQQSp8+v1zuJzbqUDRkvRuvPh0n2Sq5li0OJfQ== X-Received: by 2002:a05:6a00:4396:b0:6cb:8bb7:dfb5 with SMTP id bt22-20020a056a00439600b006cb8bb7dfb5mr17375576pfb.25.1701190569871; Tue, 28 Nov 2023 08:56:09 -0800 (PST) Received: from localhost (dhcp-72-253-202-210.hawaiiantel.net. [72.253.202.210]) by smtp.gmail.com with ESMTPSA id q4-20020a631f44000000b005acd5d7e11bsm9690803pgm.35.2023.11.28.08.56.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Nov 2023 08:56:09 -0800 (PST) Sender: Tejun Heo Date: Tue, 28 Nov 2023 06:56:08 -1000 From: Tejun Heo To: Waiman Long Cc: Zefan Li , Johannes Weiner , Andrew Morton , Michal Hocko , Frederic Weisbecker , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Mrunal Patel , Ryan Phillips , Brent Rowsell , Peter Hunt Subject: Re: [PATCH-cgroup 2/2] cgroup/cpuset: Include isolated cpuset CPUs in cpu_is_isolated() check Message-ID: References: <20231127041956.266026-1-longman@redhat.com> <20231127041956.266026-3-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231127041956.266026-3-longman@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Sun, Nov 26, 2023 at 11:19:56PM -0500, Waiman Long wrote: > +bool cpuset_cpu_is_isolated(int cpu) > +{ > + unsigned int seq; > + bool ret; > + > + do { > + seq = read_seqcount_begin(&isolcpus_seq); > + ret = cpumask_test_cpu(cpu, isolated_cpus); > + } while (read_seqcount_retry(&isolcpus_seq, seq)); > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpuset_cpu_is_isolated); We're testing a bit in a bitmask. I don't think we need to worry about value integrity from RMW updates being broken up. ie. We can just test the bit without seqlock and drop the first patch? Thanks. -- tejun