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 X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33F94C433ED for ; Mon, 10 May 2021 14:39:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 178B8613C2 for ; Mon, 10 May 2021 14:39:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244185AbhEJOkx (ORCPT ); Mon, 10 May 2021 10:40:53 -0400 Received: from foss.arm.com ([217.140.110.172]:59868 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237522AbhEJOiC (ORCPT ); Mon, 10 May 2021 10:38:02 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8602B31B; Mon, 10 May 2021 07:36:57 -0700 (PDT) Received: from e113632-lin (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D53CB3F719; Mon, 10 May 2021 07:36:55 -0700 (PDT) From: Valentin Schneider To: Yejune Deng , mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, Yejune Deng Subject: Re: [PATCH v2] lib/smp_processor_id: Use is_percpu_thread() check affinity In-Reply-To: <1620654238-1410-1-git-send-email-yejunedeng@gmail.com> References: <87pmxyj1tr.mognet@arm.com> <1620654238-1410-1-git-send-email-yejunedeng@gmail.com> Date: Mon, 10 May 2021 15:36:50 +0100 Message-ID: <87mtt2irjx.mognet@arm.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/05/21 21:43, Yejune Deng wrote: > Use is_percpu_thread() instead of 'current->nr_cpus_allowed == 1', > and add PF_NO_SETAFFINITY flag in init_idle().This would be nice to > the sched_setaffinity(), and it also more readable. > > v1->v2: > - add PF_NO_SETAFFINITY flag in init_idle(). > > Signed-off-by: Yejune Deng > --- > kernel/sched/core.c | 2 +- > lib/smp_processor_id.c | 6 +----- > 2 files changed, 2 insertions(+), 6 deletions(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 9143163..82e21ea 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -7446,7 +7446,7 @@ void init_idle(struct task_struct *idle, int cpu) > > idle->state = TASK_RUNNING; > idle->se.exec_start = sched_clock(); > - idle->flags |= PF_IDLE; > + idle->flags |= PF_IDLE | PF_NO_SETAFFINITY; Thanks for spinning a v2! Peter reminded me that it's not the only flag the idle task is missing, so I went and wrote something to make the idle task really look like a run of the mill pcpu kthread. I'll bundle your v1 with it.