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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 81582C54791 for ; Wed, 13 Mar 2024 12:28:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=da4Sw3FwV2D4UQHiM4fhwbh1wfkdIddBa+R6VT74R0Y=; b=JjsmAi2pOOiZrG ybfYPt6pu/JNpcN/8D+SVWqjixgwY0/wtyfMXVo/tMd0ffsIxL3k1FKcEJ1l1skTb6raK6akJ7Nc3 +9KwliVTs1kCVQvb963VmLcjQ+wCRs82HjMykP8iPOq0hWNQaIWYzrxUvlOsgnT3/NFA7KtJy7syn FcK5HtGYz/QiZeUBJL7Kn7+WuV36KNlj/Fh7BvPt2PS0jPxtvAJ6uxYp9ighqVXGm2dxaWyOhOr8h ZvPEuCY09r7vfOTZSD9RMup62otlsYNGXMrzEG1tbQi/dwnfIyjRQqzowUDtbz6U9Bj9GwWvwtzs5 TPgjhEU6+0/S8wt9vd4g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rkNiE-0000000A45R-29mN; Wed, 13 Mar 2024 12:28:02 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rkNiB-0000000A451-2kRm for linux-arm-kernel@lists.infradead.org; Wed, 13 Mar 2024 12:28:01 +0000 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 055B51007; Wed, 13 Mar 2024 05:28:33 -0700 (PDT) Received: from localhost (ionvoi01-desktop.cambridge.arm.com [10.2.78.69]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BAD9F3F762; Wed, 13 Mar 2024 05:27:55 -0700 (PDT) Date: Wed, 13 Mar 2024 12:27:53 +0000 From: Ionela Voinescu To: Beata Michalska Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, vanshikonda@os.amperecomputing.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 Subject: Re: [PATCH v3 0/3] Add support for AArch64 AMUv1-based arch_freq_get_on_cpu Message-ID: References: <20240312083431.3239989-1-beata.michalska@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240312083431.3239989-1-beata.michalska@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240313_052759_797397_920DF92B X-CRM114-Status: GOOD ( 18.92 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hey, On Tuesday 12 Mar 2024 at 08:34:28 (+0000), 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. > > 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 > > 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 (2): > 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 > Should there have been a patch that adds a call to arch_freq_get_on_cpu() from show_cpuinfo_cur_freq() as well? My understanding from this [1] thread and others referenced there is that was something we wanted. [1] https://lore.kernel.org/lkml/2cfbc633-1e94-d741-2337-e1b0cf48b81b@nvidia.com/ Thanks, Ionela. > arch/arm64/kernel/topology.c | 116 +++++++++++++++++++++++++++++++---- > drivers/base/arch_topology.c | 8 ++- > 2 files changed, 110 insertions(+), 14 deletions(-) > > -- > 2.25.1 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel