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 251F3126F32 for ; Tue, 5 Mar 2024 15:18:23 +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=1709651906; cv=none; b=MBLCvyKy2GbjskGU5CCI0wHoupq/T+xMt+NBv+in/1QgsoIIAXC9+vepqewVn/XQ4q9CA+bBxOkIu21AsCz6X62kBZyLVsMJy2zHWuEf+QpR10PFdLneM5zPGSW/on2whFZXRC0YZtrJXFH6A69nkZgM4yswv1JiafY/HqnWGzw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709651906; c=relaxed/simple; bh=p9voIdo9D0+0Lmf8WuL+uz0FKxiXDKJMY8lKAMlFPrE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=QviWXHWzldXCMVJuOzWCsx4MfMSOev2zIxWbZ+jGze69nUt7R3NC8vzDIm2oo2OQVfE8suznPbAytbgIjLyCBsZwkHl/XmMuXdjPEjlC70qblRoBOSVD6dWbdRPm7xw1pVKl3eQBvOFQIepmahl29QE826ZgE6ylqb/U9ilHpGs= 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 3CD111FB; Tue, 5 Mar 2024 07:19:00 -0800 (PST) Received: from [10.1.29.29] (e133047.arm.com [10.1.29.29]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 68D693F738; Tue, 5 Mar 2024 07:18:22 -0800 (PST) Message-ID: <0e2833ee-0939-44e0-82a2-520a585a0153@arm.com> Date: Tue, 5 Mar 2024 15:18:20 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] sched/fair: Remove stale FREQUENCY_UTIL comment Content-Language: en-US To: Vincent Guittot Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, dietmar.eggemann@arm.com References: <20240305095111.777525-1-christian.loehle@arm.com> From: Christian Loehle In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 05/03/2024 15:05, Vincent Guittot wrote: > On Tue, 5 Mar 2024 at 10:51, Christian Loehle wrote: >> >> effective_cpu_util() flags were removed, so remove the comment part >> mentioning it. >> >> commit 9c0b4bb7f6303 ("sched/cpufreq: Rework schedutil governor performance estimation") >> reworked effective_cpu_util() removing enum cpu_util_type. >> >> Signed-off-by: Christian Loehle >> --- >> kernel/sched/fair.c | 2 -- >> 1 file changed, 2 deletions(-) >> >> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c >> index 533547e3c90a..6b0c47d00fd3 100644 >> --- a/kernel/sched/fair.c >> +++ b/kernel/sched/fair.c >> @@ -7849,8 +7849,6 @@ eenv_pd_max_util(struct energy_env *eenv, struct cpumask *pd_cpus, >> * Performance domain frequency: utilization clamping >> * must be considered since it affects the selection >> * of the performance domain frequency. >> - * NOTE: in case RT tasks are running, by default the >> - * FREQUENCY_UTIL's utilization can be max OPP. > > Yes, it's no more accurate. > Should we update the comment instead of deleting it as the effect is > still there ? > "NOTE: in case RT tasks are running, by default the min utilization > can be max OPP." I'm fine with either and that was my first thought here, too, but it did seem like the comment was mostly placed there to justify the 'unexpected' high utilization when explicitly passing FREQUENCY_UTIL and the need to clamp it then. So removing did feel slightly more natural to me anyway. So alternatively: From: Christian Loehle Date: Tue, 5 Mar 2024 09:34:41 +0000 Subject: [PATCH] sched/fair: Remove stale FREQUENCY_UTIL mention effective_cpu_util() flags were removed, so remove mentioning of the flag. commit 9c0b4bb7f6303 ("sched/cpufreq: Rework schedutil governor performance estimation") reworked effective_cpu_util() removing enum cpu_util_type. Modify the comment accordingly. Signed-off-by: Christian Loehle --- kernel/sched/fair.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 533547e3c90a..f5151cbcd94e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7849,8 +7849,8 @@ eenv_pd_max_util(struct energy_env *eenv, struct cpumask *pd_cpus, * Performance domain frequency: utilization clamping * must be considered since it affects the selection * of the performance domain frequency. - * NOTE: in case RT tasks are running, by default the - * FREQUENCY_UTIL's utilization can be max OPP. + * NOTE: in case RT tasks are running, by default the min + * utilization can be max OPP. */ eff_util = effective_cpu_util(cpu, util, &min, &max); -- 2.34.1