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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 587C4C433EF for ; Mon, 18 Jul 2022 21:30:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DC7E46B0071; Mon, 18 Jul 2022 17:30:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D77596B0087; Mon, 18 Jul 2022 17:30:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C19C48E0001; Mon, 18 Jul 2022 17:30:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id B280F6B0071 for ; Mon, 18 Jul 2022 17:30:57 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 8AE5434F62 for ; Mon, 18 Jul 2022 21:30:57 +0000 (UTC) X-FDA: 79701515754.06.B574683 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) by imf20.hostedemail.com (Postfix) with ESMTP id 364DB1C0093 for ; Mon, 18 Jul 2022 21:30:57 +0000 (UTC) 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> ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=infradead.org header.s=desiato.20200630 header.b=EkBE3hq6; dmarc=none; spf=none (imf20.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.92.199) smtp.mailfrom=peterz@infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1658179857; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Vc3qso9ymLtA66nsgaSk3Fy1snAD6uHt7i9HTlSHNiE=; b=Luhdhs+m4aK8hHdyI7HtHACEjcrkoIsZolMyah2+h/whJ7WrEvajkqhuF7a9YsbiuvxSAR 9u+6cpVj+aprMVD/XvUc2U++/FXlO2j7NECUoZjrV4cb/qSqyGEmziDztnS/Wn4oFYH+qw DG7REUFiVrWagh49HZMY/S1TIeiYihs= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1658179857; a=rsa-sha256; cv=none; b=X2koalalK52+cMJ6dmxE/LRgbiIN/RhOaLEEun8ulfpazfllDFLoBGeOmlkAp/dGz7vmyB cKRLaQlA8NEi2l5nkCtbmEiKWcbEYT8pN8SDFt94L3MrpKjUOCD39ejRfX/l3QMQJ4Fo5T KoTuk+EAZosfDWopAmULAMjUGSvvDVE= X-Stat-Signature: 59pp7wkjxaj45nbwkqj1hentt8s9jdnh X-Rspamd-Queue-Id: 364DB1C0093 X-Rspam-User: Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=infradead.org header.s=desiato.20200630 header.b=EkBE3hq6; dmarc=none; spf=none (imf20.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.92.199) smtp.mailfrom=peterz@infradead.org X-Rspamd-Server: rspam11 X-HE-Tag: 1658179857-356554 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 >