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=-14.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 D3AFEC2D0E4 for ; Mon, 23 Nov 2020 22:14:09 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5B72E206C0 for ; Mon, 23 Nov 2020 22:14:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="PKc23DSp"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="MdzuxRNa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5B72E206C0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=78fbXA8sUHkHdypmbdM/zMHirwOEPGXFdryXbnPdqSc=; b=PKc23DSpRMbCzBwLJE2B6eUKA ofsta4PLeKz5kFea+/gcbRbtglaRReAPy44UO4vRsqfEpJeLWPXs2/ncOsX/s6XqHTQvdcsZ/EWb6 nu3iOUlNF4a/Vluh+lBuNIcLOtp8Z/y5eo63fqoHmenudSmVPxyHYDse+u8IIvcPgHRahnV6LAgLo FwoFniY/KhYjo47AKfkZbLH9LPIUSD5Pz3NHTn5WfTwSKMCL+3c2eHP/22QZHvZndMgACBFa6o0hV j8vqhIrIhco1nbK5K7CMZAwwU0qwuS45f1HM/MucxmCvKdkVZKMBEcVCab/QNrXuFfhqPre/bknDZ M6t1CUJZg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1khK5g-0001i6-B2; Mon, 23 Nov 2020 22:13:44 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1khK5c-0001h0-Dz for linux-arm-kernel@lists.infradead.org; Mon, 23 Nov 2020 22:13:43 +0000 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 A3C92206A5; Mon, 23 Nov 2020 22:13:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606169619; bh=hM7jHo8zGWWV1YNICPw/kIUF7tnOsXfBCzHM7DSHFXE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MdzuxRNaAjTWoHtlDeDAZaeRJGDegGr6iwdVkjJ6m9qRA0fiWNjMrDyNev4Pf4QI5 LiP17yfkHfJrzWPLQDlPl9boCiOxCS9cHUqBzSwWZrOkW9KL6B6jM62dMVBwxCHWlX 8oD4/sZcNIUtBNHmWTuoHcfDg4WRMQvzDSNj4wPg= Date: Mon, 23 Nov 2020 23:13:36 +0100 From: Frederic Weisbecker To: Alex Belits Subject: Re: [PATCH v5 7/9] task_isolation: don't interrupt CPUs with tick_nohz_full_kick_cpu() Message-ID: <20201123221336.GB1751@lothringen> References: <8d887e59ca713726f4fcb25a316e1e932b02823e.camel@marvell.com> <76ed0b222d2f16fb5aebd144ac0222a7f3b87fa1.camel@marvell.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <76ed0b222d2f16fb5aebd144ac0222a7f3b87fa1.camel@marvell.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201123_171340_587612_58C80D11 X-CRM114-Status: GOOD ( 19.90 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "linux-arch@vger.kernel.org" , "nitesh@redhat.com" , "pauld@redhat.com" , "catalin.marinas@arm.com" , "peterz@infradead.org" , "linux-api@vger.kernel.org" , "mtosatti@redhat.com" , "linux-kernel@vger.kernel.org" , "rostedt@goodmis.org" , "davem@davemloft.net" , "leon@sidebranch.com" , "netdev@vger.kernel.org" , "peterx@redhat.com" , "trix@redhat.com" , Prasun Kapoor , "tglx@linutronix.de" , "will@kernel.org" , "mingo@kernel.org" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Alex, On Mon, Nov 23, 2020 at 05:58:22PM +0000, Alex Belits wrote: > From: Yuri Norov > > For nohz_full CPUs the desirable behavior is to receive interrupts > generated by tick_nohz_full_kick_cpu(). But for hard isolation it's > obviously not desirable because it breaks isolation. > > This patch adds check for it. > > Signed-off-by: Yuri Norov > [abelits@marvell.com: updated, only exclude CPUs running isolated tasks] > Signed-off-by: Alex Belits > --- > kernel/time/tick-sched.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c > index a213952541db..6c8679e200f0 100644 > --- a/kernel/time/tick-sched.c > +++ b/kernel/time/tick-sched.c > @@ -20,6 +20,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -268,7 +269,8 @@ static void tick_nohz_full_kick(void) > */ > void tick_nohz_full_kick_cpu(int cpu) > { > - if (!tick_nohz_full_cpu(cpu)) > + smp_rmb(); > + if (!tick_nohz_full_cpu(cpu) || task_isolation_on_cpu(cpu)) > return; Like I said in subsequent reviews, we are not going to ignore IPIs. We must fix the sources of these IPIs instead. Thanks. > > irq_work_queue_on(&per_cpu(nohz_full_kick_work, cpu), cpu); > -- > 2.20.1 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel