From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 36B0CF50D; Fri, 2 Feb 2024 09:15:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706865333; cv=none; b=OhiT/jWZRszckjY/DgIgbhPdk6AJgBlK/SuhOcw7eXx/Z7VMl2DcnMOr7106m/uLsyKsjUCMiwkfxI20ZBO8V2fzbgLQ17QJfBO8RhYVoBhGrs4ukOYHip4PutubXN/uixB2imEi+ZJLZQuDqKgTpSijJ5h4RqV7KUXjusdeKaU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706865333; c=relaxed/simple; bh=nOB2zNCHmxLdT4OymTGgdgqRYFwfwOcpl02fc6ZMVZ4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Vq/kqRvOHzGUxM+hmuCPp9lzwemkdhE++jYvASkQIJ+5CiQVd/1y8Zovn22LEZKmP7l2WhbW/jF/VtOM05dAJM7JLlYwfcKUACiXIT1XDKDB4lWUVyVUSkg7C4z6OOYEjZbaJi2jS3LufJ9egRNscaXxoSpjp/JZbz+tE0IEUIA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9170FDA7; Fri, 2 Feb 2024 01:16:11 -0800 (PST) Received: from e129154.nice.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AF38F3F5A1; Fri, 2 Feb 2024 01:15:24 -0800 (PST) Date: Fri, 2 Feb 2024 10:14:47 +0100 From: Beata Michalska To: Ionela Voinescu Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, sumitg@nvidia.com, sudeep.holla@arm.covm, will@kernel.org, catalin.marinas@arm.com, viresh.kumar@linaro.org, rafael@kernel.org, yang@os.amperecomputing.com, linux-tegra@vger.kernel.org Subject: Re: [PATCH v2 2/2] cpufreq: Wire-up arch-flavored freq info into cpufreq_verify_current_freq Message-ID: References: <20231127160838.1403404-1-beata.michalska@arm.com> <20231127160838.1403404-3-beata.michalska@arm.com> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Hi Ionela, So sorry for relpying so late, lost if from my rader for a while ... On Tue, Nov 28, 2023 at 02:01:54PM +0000, Ionela Voinescu wrote: > Hi Beata, Sumit, > > On Monday 27 Nov 2023 at 16:08:38 (+0000), Beata Michalska wrote: > > From: Sumit Gupta > > > > When available, use arch_freq_get_on_cpu to obtain current frequency > > (usually an average reported over given period of time) > > to better align the cpufreq's view on the current state of affairs. > > This also automatically pulls in the update for cpuinfo_cur_freq sysfs > > attribute, aligning it with the scaling_cur_freq one, and thus providing > > consistent view on relevant platforms. > > > > Signed-off-by: Sumit Gupta > > [BM: Subject & commit msg] > > Signed-off-by: Beata Michalska > > --- > > drivers/cpufreq/cpufreq.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > > index 8c4f9c2f9c44..109559438f45 100644 > > --- a/drivers/cpufreq/cpufreq.c > > +++ b/drivers/cpufreq/cpufreq.c > > @@ -1756,7 +1756,8 @@ static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, b > > { > > unsigned int new_freq; > > > > - new_freq = cpufreq_driver->get(policy->cpu); > > + new_freq = arch_freq_get_on_cpu(policy->cpu); > > + new_freq = new_freq ?: cpufreq_driver->get(policy->cpu); > > Given that arch_freq_get_on_cpu() is an average frequency, it does not > seem right to me to trigger the sync & update process of > cpufreq_verify_current_freq() based on it. > > cpufreq_verify_current_freq() will at least modify the internal state of > the policy and send PRE and POST notifications, if not do a full frequency > update, based on this average frequency, which is likely different from > the current frequency, even beyond the 1MHz threshold. > Noted, will drop this change. --- BR Beata > While I believe it's okay to return this average frequency in > cpuinfo_cur_freq, I don't think it should be used as an indication of > an accurate current frequency, which is what > cpufreq_verify_current_freq() expects. > > Sumit, can you give more details on the issue at [1] and why this change > fixes it? > > [1] https://lore.kernel.org/lkml/6a5710f6-bfbb-5dfd-11cd-0cd02220cee7@nvidia.com/ > > Thank you, > Ionela. > > > if (!new_freq) > > return 0; > > > > -- > > 2.25.1 > >