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 6E34A17545 for ; Wed, 17 Jul 2024 06:58:42 +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=1721199524; cv=none; b=jOjCBr+Dcg/Hg7XAHRwsH+0oCwWcB3xazOKbPNoUYt7NIGoWCvFczdcvzdPG4oC/qtr5AEFKT1E0w+JPLB6YvH2Uxl84zZZoBuBJ520BdCWY+kWUCL62krJj9XMWIDypojBrBD7rc3hQP3RbcmiGlvKwvYucFekTQfI/Ox+drK0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721199524; c=relaxed/simple; bh=xZ8qXwERtzwvNr0QoG/aBLvGIt0aQPh89IxV0GZ9jUk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jafwf/eH01lR4Yt8hywNYIwGr+YZfkDwRyy7Ltd2YJzevjKE0JXDJGKZb/07YbPKe725X5adFv2bNpaFC1im3q/U17+59t9Uv1hf1+rBIxxEJcLCOtKX44iEO8AUM0wNFsBsFuB23bjJB8oePcSTwwGrTER19epSrfjKlitLnGQ= 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 DD02F1063; Tue, 16 Jul 2024 23:59:06 -0700 (PDT) Received: from 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 8C5383F762; Tue, 16 Jul 2024 23:58:38 -0700 (PDT) Date: Wed, 17 Jul 2024 08:58:28 +0200 From: Beata Michalska To: Vanshidhar Konda Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, ionela.voinescu@arm.com, sudeep.holla@arm.com, will@kernel.org, catalin.marinas@arm.com, vincent.guittot@linaro.org, sumitg@nvidia.com, yang@os.amperecomputing.com, lihuisong@huawei.com, viresh.kumar@linaro.org, rafael@kernel.org Subject: Re: [PATCH v6 0/4] Add support for AArch64 AMUv1-based arch_freq_get_on_cpu Message-ID: References: <20240603082154.3830591-1-beata.michalska@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@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: On Sat, Jul 13, 2024 at 05:32:43PM -0700, Vanshidhar Konda wrote: > On Mon, Jun 03, 2024 at 09:21:50AM +0100, Beata Michalska wrote: > > Introducing arm64 specific version of arch_freq_get_on_cpu, cashing on > > existing implementation for FIE and AMUv1 support: the frequency scale > > factor, updated on each sched tick, serves as a base for retrieving > > the frequency for a given CPU, representing an average frequency > > reported between the ticks - thus its accuracy is limited. > > > > The changes have been rather lightly (due to some limitations) tested on > > an FVP model. Note that some small discrepancies have been observed while > > I've tested these changes (v6) on AmpereOne system and the results look correct. > The frequency reported by scaling_cur_freq is as expected for housekeeping cpus, > idle as well as isolated cpus. > That's greatly appreciated - thank you for that! This series depends on [1] so once the relevant changes are ready will send an updated to expose the average freq through a relevant sysfs attrib. --- [1] https://lore.kernel.org/all/ZmrB_DqtmVpvG30l@arm.com/ --- Best Regards Beata > Thanks, > Vanshi > > > testing (on the model) and this is currently being investigated, though it > > should not have any significant impact on the overall results. > > > > Relevant discussions: > > [1] https://lore.kernel.org/all/20240229162520.970986-1-vanshikonda@os.amperecomputing.com/ > > [2] https://lore.kernel.org/all/7eozim2xnepacnnkzxlbx34hib4otycnbn4dqymfziqou5lw5u@5xzpv3t7sxo3/ > > [3] https://lore.kernel.org/all/20231212072617.14756-1-lihuisong@huawei.com/ > > [4] https://lore.kernel.org/lkml/ZIHpd6unkOtYVEqP@e120325.cambridge.arm.com/T/#m4e74cb5a0aaa353c60fedc6cfb95ab7a6e381e3c > > > > v6: > > - delay allocating cpumask for AMU FIE support instead of invalidating the mask > > upon failure to register cpufreq policy notifications > > - drop the change to cpufreq core (for cpuinfo_cur_freq) as this one will be > > sent as a separate change > > > > v5: > > - Fix invalid access to cpumask > > - Reworked finding reference cpu when getting the freq > > > > v4: > > - dropping seqcount > > - fixing identifying active cpu within given policy > > - skipping full dynticks cpus when retrieving the freq > > - bringing back plugging in arch_freq_get_on_cpu into cpuinfo_cur_freq > > > > v3: > > - dropping changes to cpufreq_verify_current_freq > > - pulling in changes from Ionela initializing capacity_freq_ref to 0 > > (thanks for that!) and applying suggestions made by her during last review: > > - switching to arch_scale_freq_capacity and arch_scale_freq_ref when > > reversing freq scale factor computation > > - swapping shift with multiplication > > - adding time limit for considering last scale update as valid > > - updating frequency scale factor upon entering idle > > > > v2: > > - Splitting the patches > > - Adding comment for full dyntick mode > > - Plugging arch_freq_get_on_cpu into cpufreq_verify_current_freq instead > > of in show_cpuinfo_cur_freq to allow the framework to stay more in sync > > with potential freq changes > > > > > > > > Beata Michalska (3): > > arm64: amu: Delay allocating cpumask for AMU FIE support > > arm64: Provide an AMU-based version of arch_freq_get_on_cpu > > arm64: Update AMU-based frequency scale factor on entering idle > > > > Ionela Voinescu (1): > > arch_topology: init capacity_freq_ref to 0 > > > > arch/arm64/kernel/topology.c | 145 +++++++++++++++++++++++++++++------ > > drivers/base/arch_topology.c | 8 +- > > 2 files changed, 127 insertions(+), 26 deletions(-) > > > > -- > > 2.25.1 > >