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 6878ECCA479 for ; Mon, 18 Jul 2022 21:31:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234946AbiGRVbR (ORCPT ); Mon, 18 Jul 2022 17:31:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232002AbiGRVbP (ORCPT ); Mon, 18 Jul 2022 17:31:15 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C2D4E29CA5; Mon, 18 Jul 2022 14:31:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Vc3qso9ymLtA66nsgaSk3Fy1snAD6uHt7i9HTlSHNiE=; b=EkBE3hq6xruIeTN5pEWtycoPia nTHhukDaToLTtOiyz5ifrYaL/pk2PEsOqtxeu/aJZ2V2cSPXMTmolnSS8WPs5A2KV5yTVPnrrZ1EN vOw0TUxhvDeRjpE1mx/2K3fMGW84q5XAjOK5+M7rdK7bROK809nD43PZ3epjvCcNnwPTVXcvbsDu8 u1S71EsomcWjaM9RrRzbyUezQioixsfbADKuWHNK1IwJGl3YizTAxUeifKpU6slDevnkbBMuu5SHS RQ6jCJo4M1vU85mqk4SFqv/uBiBRg8NE95nkeb0lHBIjEFKa1XB5sqocejkiCQ5PzK8hi8vOtZxSi PBFnLfzQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=worktop.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1oDYJz-004uBp-SO; Mon, 18 Jul 2022 21:30:32 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id 783B49802A7; Mon, 18 Jul 2022 23:30:31 +0200 (CEST) Date: Mon, 18 Jul 2022 23:30:31 +0200 From: Peter Zijlstra To: Yury Norov Cc: linux-kernel@vger.kernel.org, Alexander Lobakin , Alexei Starovoitov , Alexey Klimov , Andrew Morton , Andrii Nakryiko , Andy Shevchenko , Ben Segall , Christoph Lameter , Dan Williams , Daniel Borkmann , Daniel Bristot de Oliveira , Dennis Zhou , Dietmar Eggemann , Eric Dumazet , Frederic Weisbecker , Guenter Roeck , Ingo Molnar , Isabella Basso , John Fastabend , Josh Poimboeuf , Juergen Gross , Juri Lelli , KP Singh , Kees Cook , Martin KaFai Lau , Mel Gorman , Miroslav Benes , Nathan Chancellor , "Paul E . McKenney" , Randy Dunlap , Rasmus Villemoes , Sebastian Andrzej Siewior , Song Liu , Steven Rostedt , Tejun Heo , Thomas Gleixner , Valentin Schneider , Vincent Guittot , Vlastimil Babka , Yonghong Song , linux-mm@kvack.org, netdev@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH 09/16] irq: don't copy cpu affinity mask if source is equal to destination Message-ID: References: <20220718192844.1805158-1-yury.norov@gmail.com> <20220718192844.1805158-10-yury.norov@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220718192844.1805158-10-yury.norov@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 18, 2022 at 12:28:37PM -0700, Yury Norov wrote: > kernel/irq/manage.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c > index 8c396319d5ac..f9c1b21584ec 100644 > --- a/kernel/irq/manage.c > +++ b/kernel/irq/manage.c > @@ -284,7 +284,8 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask, > switch (ret) { > case IRQ_SET_MASK_OK: > case IRQ_SET_MASK_OK_DONE: > - cpumask_copy(desc->irq_common_data.affinity, mask); > + if (desc->irq_common_data.affinity != mask) > + cpumask_copy(desc->irq_common_data.affinity, mask); Seems like mostly pointless logic at this point. This is not a performance senstive operation afaik. > fallthrough; > case IRQ_SET_MASK_OK_NOCOPY: > irq_validate_effective_affinity(data); > -- > 2.34.1 >