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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 251C2C4320A for ; Wed, 4 Aug 2021 17:00:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 00AAB60F94 for ; Wed, 4 Aug 2021 17:00:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239771AbhHDRAu (ORCPT ); Wed, 4 Aug 2021 13:00:50 -0400 Received: from mail-oi1-f180.google.com ([209.85.167.180]:33410 "EHLO mail-oi1-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239640AbhHDRAt (ORCPT ); Wed, 4 Aug 2021 13:00:49 -0400 Received: by mail-oi1-f180.google.com with SMTP id 26so3673942oiy.0; Wed, 04 Aug 2021 10:00:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=XxImQQRd4D1ugKiTX4wzCD+33Wg69xMML2J4wGzPmQU=; b=bMfdquAM2XPq+dUDEdB1u8SiOtImCU9c20C0k+TfbTLTNJ5mllBYDlWh7m/MFEGT3v 5KzjA6F2lRcD14UhZMAFO/6ULyvu2JRHPsvU0EbkDBdB9urTLcU3lmB8rD549Ty/zpnh bwbw9x+wTf1QRu53AyLHl1fokPqVAl2mm8JOpcg3Kp+b3FQGO3hwHJ5hGwvw4CzntgUf GZT4Zkx1lBKs/8ZiyDqYf/PHgo908lWBsulLb47UMBTZHA0kvojPhTQGusUgtYoyI9m7 7elmEZEwSElzOyd/00juwYbBMh0dVMSEWt2cEZfKk4m4jCak1bBsSbBTRvUh34TA9urz AJAg== X-Gm-Message-State: AOAM532GOFExtvDp8d5N18+rxu+z5olqEstf+0TgWaFAW3byDcQJoMY7 rPWJfovMJSHRjTSsVApSfBCB+4SZyAUUb75CQ64= X-Google-Smtp-Source: ABdhPJx5JQpQu99HXyDJXrqIFjHkd4lBZL8Mm/gOHKvlGj/KmDBTmbAGVD0Uiumul4r+DCDkygVWzU8btsx8DtiHmEI= X-Received: by 2002:a05:6808:198c:: with SMTP id bj12mr350174oib.71.1628096435307; Wed, 04 Aug 2021 10:00:35 -0700 (PDT) MIME-Version: 1.0 References: <20210721101658.9235-1-ray.huang@amd.com> <20210803001339.GG2563957@hr-amd> In-Reply-To: <20210803001339.GG2563957@hr-amd> From: "Rafael J. Wysocki" Date: Wed, 4 Aug 2021 19:00:23 +0200 Message-ID: Subject: Re: [PATCH] cpufreq: enhance the sequency of governor change To: Huang Rui Cc: "Rafael J . Wysocki" , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 3, 2021 at 2:13 AM Huang Rui wrote: > > Ping~ I prefer the existing code, sorry. > On Wed, Jul 21, 2021 at 06:16:58PM +0800, Huang, Ray wrote: > > Keep the "success" case of governor change in the mainline of the > > function not in "if" case. And using restart_old_gov flag to indicate > > the fallback case to old governor. This is more readable and no function > > change. > > > > Signed-off-by: Huang Rui > > --- > > drivers/cpufreq/cpufreq.c | 23 +++++++++++++++-------- > > 1 file changed, 15 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > > index 802abc925b2a..4f7005ddb70c 100644 > > --- a/drivers/cpufreq/cpufreq.c > > +++ b/drivers/cpufreq/cpufreq.c > > @@ -2545,18 +2545,25 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, > > /* start new governor */ > > policy->governor = new_gov; > > ret = cpufreq_init_governor(policy); > > - if (!ret) { > > - ret = cpufreq_start_governor(policy); > > - if (!ret) { > > - pr_debug("governor change\n"); > > - sched_cpufreq_governor_change(policy, old_gov); > > - return 0; > > - } > > + if (ret) > > + goto restart_old_gov; > > + > > + ret = cpufreq_start_governor(policy); > > + if (ret) { > > cpufreq_exit_governor(policy); > > + goto restart_old_gov; > > } > > > > + pr_debug("governor change\n"); > > + > > + sched_cpufreq_governor_change(policy, old_gov); > > + > > + return 0; > > + > > +restart_old_gov: > > /* new governor failed, so re-start old one */ > > - pr_debug("starting governor %s failed\n", policy->governor->name); > > + pr_debug("starting governor %s failed\n", > > + policy->governor->name); > > if (old_gov) { > > policy->governor = old_gov; > > if (cpufreq_init_governor(policy)) > > --