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[209.132.180.67]) by mx.google.com with ESMTP id r11-v6si8875952pgj.46.2018.09.07.07.18.35; Fri, 07 Sep 2018 07:18:51 -0700 (PDT) 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="LzRt3K/B"; 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 S1728493AbeIGPF3 (ORCPT + 99 others); Fri, 7 Sep 2018 11:05:29 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:52668 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728041AbeIGPF3 (ORCPT ); Fri, 7 Sep 2018 11:05:29 -0400 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=B+dRi740mod0o9eX5oP25W/39hKnSCs5AlkFv7wdLzE=; b=LzRt3K/BCZhQ62ztfj5+Vuwzb 1Wrcml2mW7uBnYKGj5V5s5xKbcv1VCEn8RG961+8Ly+wcTXcPgGcA9C3RB1jdthOjo27bO9TcBQ6B 3ljyLbGR9O8e2PewO8nbTmHxph5auSHS5w8ZZPui1rT5wSXfB5K+yczMkgMHsbzEmA2bLZlS6Vhy+ tJo9euLKQQsjKM5SoGYF8G0O916XE0j56/4JXQ13AmSeZ4KW6ehApLcpPpcKuJCL99X4l6r1E6W69 dyDZSDqBkcTdcX2FG2DZkzrzOdHCysYo3xZEI2bkNNTE4Dp+HFIVk0ba1ih+uf4FntCsdVEVyVcGy biL11IbRg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fyDwh-0000ba-PJ; Fri, 07 Sep 2018 10:24:59 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 44C86201F9C46; Fri, 7 Sep 2018 12:24:58 +0200 (CEST) Date: Fri, 7 Sep 2018 12:24:58 +0200 From: Peter Zijlstra To: Johannes Weiner Cc: Ingo Molnar , Andrew Morton , Linus Torvalds , Tejun Heo , Suren Baghdasaryan , Daniel Drake , Vinayak Menon , Christopher Lameter , Peter Enderborg , Shakeel Butt , Mike Galbraith , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 8/9] psi: pressure stall information for CPU, memory, and IO Message-ID: <20180907102458.GP24106@hirez.programming.kicks-ass.net> References: <20180828172258.3185-1-hannes@cmpxchg.org> <20180828172258.3185-9-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180828172258.3185-9-hannes@cmpxchg.org> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 28, 2018 at 01:22:57PM -0400, Johannes Weiner wrote: > +static void psi_clock(struct work_struct *work) > +{ > + struct delayed_work *dwork; > + struct psi_group *group; > + bool nonidle; > + > + dwork = to_delayed_work(work); > + group = container_of(dwork, struct psi_group, clock_work); > + > + /* > + * If there is task activity, periodically fold the per-cpu > + * times and feed samples into the running averages. If things > + * are idle and there is no data to process, stop the clock. > + * Once restarted, we'll catch up the running averages in one > + * go - see calc_avgs() and missed_periods. > + */ > + > + nonidle = update_stats(group); > + > + if (nonidle) { > + unsigned long delay = 0; > + u64 now; > + > + now = sched_clock(); > + if (group->next_update > now) > + delay = nsecs_to_jiffies(group->next_update - now) + 1; > + schedule_delayed_work(dwork, delay); > + } > +} Just a little nit; I would expect a function called *clock() to return a time.