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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 60A6DC43441 for ; Sun, 11 Nov 2018 15:20:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B2B7208A3 for ; Sun, 11 Nov 2018 15:20:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="SwMQGd6p" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1B2B7208A3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728628AbeKLBJb (ORCPT ); Sun, 11 Nov 2018 20:09:31 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:35520 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728331AbeKLBJb (ORCPT ); Sun, 11 Nov 2018 20:09:31 -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=dOX9J4ag4QAFVVXuroGsDYZFFUeCHh8UKE0Sm9ltKsY=; b=SwMQGd6p+ogiX0hjsmdsAKMeF PnXpzMnIcDqurw1dbicnshfrdkDG70ouSlGc9uIicL6emkZkDLJBqFIgry9E/VCN9wi95MOTFJeZ+ eqxfJBHXeLRb/pLWN4W39YpY7sxww0s78X6irFlv9DEijI1X0FltLm1jEDqEbBEuMO3QJuJcv5bTf 6siwsUqwpHJPRK3O1LrBcYOTa39gAykT+th9g5OoVD8ASZAJjJPt9/Lig1UiAHjZelJasHZwSOOvB xVIwS/D3y8o5xlo+T6EFzIAkebXzjHFxXjIF+JMp+HBMMgMXmu+al/0sIaDvIHHxIZ5H4gV+cJzT4 fYNk6FWgQ==; Received: from [64.114.255.97] (helo=worktop) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gLrXP-0007qU-8g; Sun, 11 Nov 2018 15:20:35 +0000 Received: by worktop (Postfix, from userid 1000) id B8B1C6E0405; Sun, 11 Nov 2018 16:20:34 +0100 (CET) Date: Sun, 11 Nov 2018 16:20:34 +0100 From: Peter Zijlstra To: "Rafael J. Wysocki" Cc: Linux PM , Giovanni Gherdovich , Doug Smythies , Srinivas Pandruvada , LKML , Frederic Weisbecker , Mel Gorman , Daniel Lezcano Subject: Re: [RFC/RFT][PATCH v5] cpuidle: New timer events oriented governor for tickless systems Message-ID: <20181111152034.GC3021@worktop> References: <102783770.7hZjAahU8c@aspire.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <102783770.7hZjAahU8c@aspire.rjw.lan> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 08, 2018 at 06:25:07PM +0100, Rafael J. Wysocki wrote: > +/* > + * The SPIKE value is added to metrics when they grow and the DECAY_SHIFT value > + * is used for decreasing metrics on a regular basis. > + */ > +#define SPIKE 1024 > +#define DECAY_SHIFT 3 > + if (idx_timer >= 0) { > + unsigned int hits = cpu_data->states[idx_timer].hits; > + unsigned int misses = cpu_data->states[idx_timer].misses; > + > + hits -= hits >> DECAY_SHIFT; > + misses -= misses >> DECAY_SHIFT; > + > + if (idx_timer > idx_hit) { > + misses += SPIKE; > + if (idx_hit >= 0) > + cpu_data->states[idx_hit].early_hits += SPIKE; > + } else { > + hits += SPIKE; > + } > + > + cpu_data->states[idx_timer].misses = misses; > + cpu_data->states[idx_timer].hits = hits; > + } That's a pulse-density-modulator, with a signal bound of: 1024 == x/8 -> x := 8192 Anyway; I would suggest s/SPIKE/PULSE/ because of that.