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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 B32DAC43381 for ; Mon, 11 Mar 2019 11:59:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 88215206BA for ; Mon, 11 Mar 2019 11:59:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727080AbfCKL7L (ORCPT ); Mon, 11 Mar 2019 07:59:11 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:55368 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726688AbfCKL7K (ORCPT ); Mon, 11 Mar 2019 07:59:10 -0400 Received: from 79.184.254.189.ipv4.supernova.orange.pl (79.184.254.189) (HELO aspire.rjw.lan) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.213) id cb9b810278c7f12d; Mon, 11 Mar 2019 12:59:08 +0100 From: "Rafael J. Wysocki" To: Linux PM Cc: LKML , Srinivas Pandruvada , Doug Smythies Subject: [PATCH] cpufreq: intel_pstate: Fix up iowait_boost computation Date: Mon, 11 Mar 2019 12:57:25 +0100 Message-ID: <2396291.FVDonix7jd@aspire.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki After commit b8bd1581aa61 ("cpufreq: intel_pstate: Rework iowait boosting to be less aggressive") the handling of the case when the SCHED_CPUFREQ_IOWAIT flag is set again after a few iterations of intel_pstate_update_util() is a bit inconsistent, because the new value of cpu->iowait_boost may be lower than ONE_EIGHTH_FP if it was set before, but has not dropped down to zero just yet. Fix that up by ensuring that the new value of cpu->iowait_boost will always be at least ONE_EIGHTH_FP then. Fixes: b8bd1581aa61 ("cpufreq: intel_pstate: Rework iowait boosting to be less aggressive") Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-pm/drivers/cpufreq/intel_pstate.c =================================================================== --- linux-pm.orig/drivers/cpufreq/intel_pstate.c +++ linux-pm/drivers/cpufreq/intel_pstate.c @@ -1806,7 +1806,7 @@ static void intel_pstate_update_util(str /* Start over if the CPU may have been idle. */ if (delta_ns > TICK_NSEC) { cpu->iowait_boost = ONE_EIGHTH_FP; - } else if (cpu->iowait_boost) { + } else if (cpu->iowait_boost >= ONE_EIGHTH_FP) { cpu->iowait_boost <<= 1; if (cpu->iowait_boost > int_tofp(1)) cpu->iowait_boost = int_tofp(1);