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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 4B1BAC433ED for ; Tue, 6 Apr 2021 13:07:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1AA83613A3 for ; Tue, 6 Apr 2021 13:07:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240666AbhDFNHJ (ORCPT ); Tue, 6 Apr 2021 09:07:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232492AbhDFNHH (ORCPT ); Tue, 6 Apr 2021 09:07:07 -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 7040FC06174A for ; Tue, 6 Apr 2021 06:06:59 -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=j2c2vVMgDzxpq/NDOYVmtTlifBkvHOiRtuxxd/tOLOU=; b=Ixh7YWXW5iwUXA8g5hR5tO3hV3 wG45ru/AtScmmfh4oKJc7dIeVodRxISsutJcgwkG9yFZqkTlLA7CVe1Ec4w4Z1Hxk8qZWitgeSwsv jcUHhpJp0bibrHmXorX+zDtP08l7w1Z6XhcuZmrlhIm8smsEC52HhCsXsba4MBSIetev/4n1s/HA9 /ta1+1Nwx6e1jr4cnU7gQwGVP1w9XL/DGbTU0kHlez817m9M3PEY/rTs5x+Q1BGdF1Cdn9r6w5OtB QjXKrie7hTVeFyqazHLJ73n+/21Lx4lmXovm3/441fFWovu2Q4EYIoC21y58/rifTVfLwT15zcSA8 7y1mFazg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lTlPY-002f9I-BA; Tue, 06 Apr 2021 13:06:28 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 08F82304B54; Tue, 6 Apr 2021 15:06:23 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 141002C1D2B56; Tue, 6 Apr 2021 13:18:09 +0200 (CEST) Date: Tue, 6 Apr 2021 13:18:09 +0200 From: Peter Zijlstra To: Ricardo Neri Cc: Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Len Brown , Srinivas Pandruvada , Tim Chen , Aubrey Li , "Ravi V. Shankar" , Ricardo Neri , Quentin Perret , "Joel Fernandes (Google)" , linux-kernel@vger.kernel.org, Aubrey Li , Ben Segall , Daniel Bristot de Oliveira Subject: Re: [PATCH 3/4] sched/fair: Consider SMT in ASYM_PACKING load balance Message-ID: References: <20210406041108.7416-1-ricardo.neri-calderon@linux.intel.com> <20210406041108.7416-4-ricardo.neri-calderon@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210406041108.7416-4-ricardo.neri-calderon@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 05, 2021 at 09:11:07PM -0700, Ricardo Neri wrote: > +static bool cpu_group_is_smt(int cpu, struct sched_group *sg) > +{ > +#ifdef CONFIG_SCHED_SMT > + if (!static_branch_likely(&sched_smt_present)) > + return false; > + > + if (sg->group_weight == 1) > + return false; > + > + if (cpumask_weight(cpu_smt_mask(cpu)) == 1) > + return false; Please explain this condition. Why is it required? > + return cpumask_equal(sched_group_span(sg), cpu_smt_mask(cpu)); > +#else > + return false; > +#endif > +}