From mboxrd@z Thu Jan 1 00:00:00 1970 From: Prarit Bhargava Subject: Re: [PATCH 1/2] cpufreq, intel_pstate, Fix limits->max_policy_pct rounding error Date: Fri, 20 Nov 2015 10:43:54 -0500 Message-ID: <564F3FBA.6030806@redhat.com> References: <1448022757-7856-1-git-send-email-prarit@redhat.com> <1448022757-7856-2-git-send-email-prarit@redhat.com> <20151120131833.GD3957@ubuntu> <564F37C8.60307@redhat.com> <20151120151944.GE3957@ubuntu> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:48803 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1163001AbbKTPn4 (ORCPT ); Fri, 20 Nov 2015 10:43:56 -0500 In-Reply-To: <20151120151944.GE3957@ubuntu> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Viresh Kumar Cc: linux-kernel@vger.kernel.org, Srinivas Pandruvada , Len Brown , Alexandra Yates , Kristen Carlson Accardi , "Rafael J. Wysocki" , linux-pm@vger.kernel.org On 11/20/2015 10:19 AM, Viresh Kumar wrote: > On 20-11-15, 10:10, Prarit Bhargava wrote: >>>> limits->max_policy_pct = clamp_t(int, limits->max_policy_pct, 0 , 100); >>> >>> And put this after the later one ? >>> >>>> + limits->max_policy_pct = DIV_ROUND_UP(policy->max * 100, >>>> + policy->cpuinfo.max_freq); >>>> >>>> /* Normalize user input to [min_policy_pct, max_policy_pct] */ >>>> limits->min_perf_pct = max(limits->min_policy_pct, >>> >>> Sure you tested it ? :) >> >> Oops -- and yeah, tested. It works because I rewrite the value of >> max_policy_pct :). I'll repost shortly. > > But we aren't doing below anymore, doesn't this change the > calculations at all? > > limits->max_policy_pct = clamp_t(int, limits->max_policy_pct, 0 , 100); The clamp only confines the max_policy between 0 and 100. AFAIK it doesn't make any change tothe value of limits->max_policy_pct unless it was outside of that range. P. >