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 DD858745F1 for ; Fri, 12 Jan 2024 14:23:45 +0000 (UTC) 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 987091FB; Fri, 12 Jan 2024 06:24:31 -0800 (PST) Received: from [192.168.178.6] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7BD8D3F5A1; Fri, 12 Jan 2024 06:23:43 -0800 (PST) Message-ID: <4405adb5-0b16-4716-9542-47d8bb1737ee@arm.com> Date: Fri, 12 Jan 2024 15:23:41 +0100 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: [GIT PULL] Scheduler changes for v6.8 Content-Language: en-US To: Vincent Guittot , Linus Torvalds Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner , Juri Lelli , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider References: From: Dietmar Eggemann In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/01/2024 19:16, Vincent Guittot wrote: > On Thu, 11 Jan 2024 at 18:53, Linus Torvalds > wrote: >> >> On Thu, 11 Jan 2024 at 09:45, Linus Torvalds >> wrote: >>> >>> On Thu, 11 Jan 2024 at 00:11, Vincent Guittot >>> wrote: >>>> >>>> Could you confirm that cpufreq governor is schedutil and the driver is >>>> amd-pstate on your system ? >>> >>> schedutil yes, amd-pstate no. I actually just use acpi_cpufreq >> >> Bah. Hit 'send' mistakenly too soon, thus the abrupt end and >> unfinished quoting removal. >> >> And don't ask me why it's acpi_pstate-driven. I have X86_AMD_PSTATE=y, but >> >> /sys/devices/system/cpu/cpufreq/policy0/scaling_driver >> >> clearly says 'acpi-cpufreq'. Maybe I'm looking in the wrong place. My dmesg says > > That seems to be the right place to look > >> >> amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled >> >> which is presumably the reason my machine uses acpi-pstate. >> >> I will also test out your other questions, but I need to go back and >> do more pull requests first. > > ok, thanks > > I'm going to continue checking what else could trigger such regression > having in mind that your system should not have beeb impacted by this > changes I can't see the regression on my 20-core (40-thread) Intel Xeon CPU E5-2690 v2 with 'schedutil' and 'acpi-cpufreq'. f12560779f9d - sched/cpufreq: Rework iowait boost <- (w/ patches) 9c0b4bb7f630 - sched/cpufreq: Rework schedutil governor performance estimation 50181c0cff31 - sched/pelt: Avoid underestimation of task utilization <- (base) ... # cpufreq-info -c 0 -e ... analyzing CPU 0: driver: acpi-cpufreq CPUs which run at the same hardware frequency: 0 CPUs which need to have their frequency coordinated by software: 0 maximum transition latency: 10.0 us. hardware limits: 1.20 GHz - 3.00 GHz available frequency steps: 3.00 GHz, 3.00 GHz, 2.90 GHz, 2.70 GHz, 2.60 GHz, 2.50 GHz, 2.40 GHz, 2.20 GHz, 2.10 GHz, 2.00 GHz, 1.80 GHz, 1.70 GHz, 1.60 GHz, 1.50 GHz, 1.30 GHz, 1.20 GHz available cpufreq governors: conservative, ondemand, userspace, powersave, performance, schedutil current policy: frequency should be within 1.20 GHz and 3.00 GHz. The governor "schedutil" may decide which speed to use within this range. current CPU frequency is 1.20 GHz (asserted by call to hardware). cpufreq is still fast-switching, so no schedutil 'sugov' DL threads.