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 76BDCC433EF for ; Mon, 18 Jul 2022 21:38:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 083E76B0071; Mon, 18 Jul 2022 17:38:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F27D36B0073; Mon, 18 Jul 2022 17:38:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DA2258E0001; Mon, 18 Jul 2022 17:38:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id C3DB56B0071 for ; Mon, 18 Jul 2022 17:38:00 -0400 (EDT) Received: from smtpin31.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 994DA34E37 for ; Mon, 18 Jul 2022 21:38:00 +0000 (UTC) X-FDA: 79701533520.31.7A2CF43 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf26.hostedemail.com (Postfix) with ESMTP id 497E814006A for ; Mon, 18 Jul 2022 21:38:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=rVLafi1o5Yx4dEmDVl1W6TD+Wq81qe2gQS1q1eagFNg=; b=XNXz2eylmoKJZEcMgJYBDtZRWQ UgCNyujXA2CvqsLeKDNjCvm4l+VaJDREh5d21Sc6wixC5dZpvC+1I3/oOgK0earWPP0OdeHz5xLYl z4NZCeSNOuJq3k5DC8gpEa8gxFEx0weg8h1gAsSAY1Hsn7LtwY7FcmlgubkjJ5LEVI5fTGojrl89w gBR9kyMnPnVD4nOeqL+n9KMaHjEN4LgzSwYM6oSG/FDwLCYbWryCvl7pfi2yiIV14qRFPSQv9U0kA C4rDHWyeDBG9qtCG4IR4fF+qPLt4N5hUyIPfFJVl/MJaaoOB0/e/4qRFvObFXcMzqIW6vTA/E4ySz +Bbon1JQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=worktop.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1oDYR1-00D3Lw-Va; Mon, 18 Jul 2022 21:37:48 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id 6DF1B9802A7; Mon, 18 Jul 2022 23:37:47 +0200 (CEST) Date: Mon, 18 Jul 2022 23:37:47 +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 15/16] sched/topology: optimize topology_span_sane() Message-ID: References: <20220718192844.1805158-1-yury.norov@gmail.com> <20220718192844.1805158-16-yury.norov@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220718192844.1805158-16-yury.norov@gmail.com> ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1658180280; a=rsa-sha256; cv=none; b=NLp8vMySqELijyeCsV9a/O++7xWz+fDRGnRMQaa6O4C5WyG3ZzzvXDZRX7ijupIOYR2t/2 /5Cd19xjLv5BoP8VDKp/fCo/jbsbBF1/CGu128q354NTVGvRht4b1oRofdXC+a4L/cp3bE x4QHDjSuaOSdc41JcEUq0yCdXYMhEoc= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=XNXz2eyl; spf=none (imf26.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=peterz@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1658180280; 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=rVLafi1o5Yx4dEmDVl1W6TD+Wq81qe2gQS1q1eagFNg=; b=gWwZ3YukyWaFdpeQTcU8sPtPd6Yn7avhkuybtXSU6BNS+1SlZR5sPcUVFJL6tax4hZrCcj b+HL+LcY1cldWcMKUaGxGG/Bi4r4DoRuMNdgYagmozk2zYRhuQI2ZaSlLyLZwX8XUHBZuO 4+0qd2M3IC9RFpqSNsvQP7Zo4gjI/Os= X-Rspamd-Queue-Id: 497E814006A Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=XNXz2eyl; spf=none (imf26.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=peterz@infradead.org; dmarc=none X-Rspam-User: X-Rspamd-Server: rspam06 X-Stat-Signature: wmco94syinqyznmm5cd6zwgxz3qkk1rx X-HE-Tag: 1658180280-550746 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 12:28:43PM -0700, Yury Norov wrote: > kernel/sched/topology.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c > index 05b6c2ad90b9..ad32d0a43424 100644 > --- a/kernel/sched/topology.c > +++ b/kernel/sched/topology.c > @@ -2211,6 +2211,8 @@ static struct sched_domain *build_sched_domain(struct sched_domain_topology_leve > static bool topology_span_sane(struct sched_domain_topology_level *tl, > const struct cpumask *cpu_map, int cpu) > { > + const struct cpumask *mc = tl->mask(cpu); > + const struct cpumask *mi; > int i; > > /* NUMA levels are allowed to overlap */ > @@ -2226,14 +2228,18 @@ static bool topology_span_sane(struct sched_domain_topology_level *tl, > for_each_cpu(i, cpu_map) { > if (i == cpu) > continue; > + > + mi = tl->mask(i); > + if (mi == mc) > + continue; > + > /* > * We should 'and' all those masks with 'cpu_map' to exactly > * match the topology we're about to build, but that can only > * remove CPUs, which only lessens our ability to detect > * overlaps > */ > - if (!cpumask_equal(tl->mask(cpu), tl->mask(i)) && > - cpumask_intersects(tl->mask(cpu), tl->mask(i))) > + if (!cpumask_equal(mc, mi) && cpumask_intersects(mc, mi)) > return false; > } This is once again a super slow path; but I don't suppose you're making the code worse in this case.