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[209.132.180.67]) by mx.google.com with ESMTP id f15-v6si4840333plr.336.2018.02.16.11.10.15; Fri, 16 Feb 2018 11:10:29 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@infradead.org header.s=bombadil.20170209 header.b=sSXuo6MU; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1032245AbeBPNrL (ORCPT + 99 others); Fri, 16 Feb 2018 08:47:11 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:40276 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1032212AbeBPNrJ (ORCPT ); Fri, 16 Feb 2018 08:47:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=UabflJxTLt5+e7ZJThgnbFv7HK+jqTg6wk62cZTp1Yc=; b=sSXuo6MU1N/VIrvrcc78xe4XT 8noXxQ+MOdfimQ65GjisuH5mUDIglD+/ySAleGGhY9ZCGy8IMniz4DjwgwtXM8BICifBzbnM5U6Cp Fy1OcshW6HmqAl3/6KfqtgyiznhlwKxlWyJi6N5B10e6V8d1eHej3jHPf/0HEQEOE4cXMDPbBPAE1 UwkS9Z8oLBN0Jp0aSOSMyKDUvNalM/O6AQO2cJzJ52cdjts6fx7g0uCcfXBWVih6v+Cbx9DPwqmZ2 9kMs3mwgGkKR8WPoKRzed6muht8VhaW17qgku/N46OxL6po9jHD53ee18YJRhec19jvVfBGgVqgkK Gv1g8wWxA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.89 #1 (Red Hat Linux)) id 1emgLy-0005fg-3E; Fri, 16 Feb 2018 13:47:06 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 24B7320587E64; Fri, 16 Feb 2018 14:47:04 +0100 (CET) Date: Fri, 16 Feb 2018 14:47:04 +0100 From: Peter Zijlstra To: Morten Rasmussen Cc: mingo@redhat.com, valentin.schneider@arm.com, dietmar.eggemann@arm.com, vincent.guittot@linaro.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/7] sched: Add static_key for asymmetric cpu capacity optimizations Message-ID: <20180216134704.GE25201@hirez.programming.kicks-ass.net> References: <1518711654-23503-1-git-send-email-morten.rasmussen@arm.com> <1518711654-23503-2-git-send-email-morten.rasmussen@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1518711654-23503-2-git-send-email-morten.rasmussen@arm.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 15, 2018 at 04:20:48PM +0000, Morten Rasmussen wrote: > +static void update_asym_cpucapacity(int cpu) > +{ > + if (!static_branch_unlikely(&sched_asym_cpucapacity) && > + lowest_flag_domain(cpu, SD_ASYM_CPUCAPACITY)) > + static_branch_enable(&sched_asym_cpucapacity); > +} That looks odd, why not just: if (lowest_flag_domain(cpu, SD_ASYM_CPUCAPACITY)) static_branch_enable(&sched_asym_cpucapacity); ? possibly with: else static_branch_disable(&sched_asym_cpucapacity); if you want to play funny games :-)