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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 D0E6AC2D0E4 for ; Mon, 23 Nov 2020 22:29:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B76A20715 for ; Mon, 23 Nov 2020 22:29:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ixP3Yo9U" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729842AbgKWW3L (ORCPT ); Mon, 23 Nov 2020 17:29:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:45868 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729058AbgKWW3L (ORCPT ); Mon, 23 Nov 2020 17:29:11 -0500 Received: from localhost (unknown [176.167.152.233]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 18DD1206D5; Mon, 23 Nov 2020 22:29:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606170550; bh=xXNk1SHeG0DaBJJsaGjypi7ccMGVaxlbxK413/BOw4o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ixP3Yo9U3LEyuDTmCaRqPijWNey8CBiHdJfyFxnoMlHmfOcb4S2gKkJlPWpPLtHQg kvc5oiRGqS0ZAHNBtaEIoKLepU2ALrH0nhLNWTasgX6yRBBbAHzbf8Q61ptTFdZKh4 xqCRZIkjtAaouTmcyAvseDOYLX1ZGfEePoTtoxDU= Date: Mon, 23 Nov 2020 23:29:07 +0100 From: Frederic Weisbecker To: Alex Belits Cc: "nitesh@redhat.com" , Prasun Kapoor , "linux-api@vger.kernel.org" , "davem@davemloft.net" , "trix@redhat.com" , "mingo@kernel.org" , "catalin.marinas@arm.com" , "rostedt@goodmis.org" , "linux-kernel@vger.kernel.org" , "peterx@redhat.com" , "tglx@linutronix.de" , "linux-arch@vger.kernel.org" , "mtosatti@redhat.com" , "will@kernel.org" , "peterz@infradead.org" , "leon@sidebranch.com" , "linux-arm-kernel@lists.infradead.org" , "pauld@redhat.com" , "netdev@vger.kernel.org" Subject: Re: [PATCH v5 9/9] task_isolation: kick_all_cpus_sync: don't kick isolated cpus Message-ID: <20201123222907.GC1751@lothringen> References: <8d887e59ca713726f4fcb25a316e1e932b02823e.camel@marvell.com> <3236b13f42679031960c5605be20664e90e75223.camel@marvell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3236b13f42679031960c5605be20664e90e75223.camel@marvell.com> Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Mon, Nov 23, 2020 at 05:58:42PM +0000, Alex Belits wrote: > From: Yuri Norov > > Make sure that kick_all_cpus_sync() does not call CPUs that are running > isolated tasks. > > Signed-off-by: Yuri Norov > [abelits@marvell.com: use safe task_isolation_cpumask() implementation] > Signed-off-by: Alex Belits > --- > kernel/smp.c | 14 +++++++++++++- > 1 file changed, 13 insertions(+), 1 deletion(-) > > diff --git a/kernel/smp.c b/kernel/smp.c > index 4d17501433be..b2faecf58ed0 100644 > --- a/kernel/smp.c > +++ b/kernel/smp.c > @@ -932,9 +932,21 @@ static void do_nothing(void *unused) > */ > void kick_all_cpus_sync(void) > { > + struct cpumask mask; > + > /* Make sure the change is visible before we kick the cpus */ > smp_mb(); > - smp_call_function(do_nothing, NULL, 1); > + > + preempt_disable(); > +#ifdef CONFIG_TASK_ISOLATION > + cpumask_clear(&mask); > + task_isolation_cpumask(&mask); > + cpumask_complement(&mask, &mask); > +#else > + cpumask_setall(&mask); > +#endif > + smp_call_function_many(&mask, do_nothing, NULL, 1); > + preempt_enable(); Same comment about IPIs here. > } > EXPORT_SYMBOL_GPL(kick_all_cpus_sync); > > -- > 2.20.1 >