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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9B35C46467 for ; Tue, 27 Dec 2022 18:49:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229533AbiL0St5 (ORCPT ); Tue, 27 Dec 2022 13:49:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229665AbiL0Stv (ORCPT ); Tue, 27 Dec 2022 13:49:51 -0500 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34520D2C8; Tue, 27 Dec 2022 10:49:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1672166990; x=1703702990; h=message-id:subject:from:to:cc:date:in-reply-to: references:mime-version:content-transfer-encoding; bh=7pXQAZMf1WL75uIYHs9KgSY6E2yOmxH87Domw3cw/lo=; b=jpJysF/UCLTQumODIhB8bCRReDK1RjX2GRbA3vc0/SetcQ/X0sj1N8do Tv8L4mCb4vhr4FmaNYjcwbGkFz5UHA7ukXbdzZaiUKgdMWW6Siev7Qw+v fQS6LTgMOo4KXPlDOL29Hux3FHeA7Me3Lr3hnAXaJzPuVwVvsM5zsZ5I2 SXtwpMHtzPBDfgTz8CdQZezVuVu+5wpHQu2spsIBR59ku4UqqztWN95TT c8/BvRncYT+tfoGiL+D8vrj3wX4jz57y5f3FtR1TOx63BLcYKF5cZRZkL IA64U/AHMgSFK5E1suMXEC5ujOAXhJPjxGhroi4JIBkBrx+71OUV6/Y3C A==; X-IronPort-AV: E=McAfee;i="6500,9779,10573"; a="318419886" X-IronPort-AV: E=Sophos;i="5.96,279,1665471600"; d="scan'208";a="318419886" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Dec 2022 10:49:49 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10573"; a="630760692" X-IronPort-AV: E=Sophos;i="5.96,279,1665471600"; d="scan'208";a="630760692" Received: from wilsona1-mobl3.amr.corp.intel.com (HELO spandruv-desk1.amr.corp.intel.com) ([10.212.223.115]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Dec 2022 10:49:49 -0800 Message-ID: Subject: Re: [PATCH 0/2] intel_pstate: fix turbo not being used after a processor is rebooted From: srinivas pandruvada To: "Rafael J. Wysocki" Cc: Pratyush Yadav , linux-pm@vger.kernel.org, Len Brown , Viresh Kumar , Robert Moore , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, devel@acpica.org Date: Tue, 27 Dec 2022 10:49:49 -0800 In-Reply-To: References: <20221221155203.11347-1-ptyadav@amazon.de> <72bcd14eef038ec9181d30b3d196b0a872f47ccb.camel@linux.intel.com> <2ed9702b67832e3e33ef352808124980206c1e95.camel@linux.intel.com> <8e2cc66f7dadcfb04099aac7c4eef0b02075c91b.camel@linux.intel.com> <33dd969d9bdb1eb93f8f2a2167efeb535455cf74.camel@linux.intel.com> <61b3d3720ac4bfd1fc8b7dcd09f58dd5a2de3cca.camel@linux.intel.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.4 (3.42.4-2.fc35) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Tue, 2022-12-27 at 19:47 +0100, Rafael J. Wysocki wrote: > On Tue, Dec 27, 2022 at 7:07 PM srinivas pandruvada > wrote: > > > > On Tue, 2022-12-27 at 18:02 +0100, Rafael J. Wysocki wrote: > > > On Tue, Dec 27, 2022 at 5:40 PM srinivas pandruvada > > > wrote: > > > > > > > > On Tue, 2022-12-27 at 16:38 +0100, Pratyush Yadav wrote: > > > > > Hi Srinivas, > > > > > > > > > > On Sat, Dec 24 2022, srinivas pandruvada wrote: > > > > > > > > > > > On Fri, 2022-12-23 at 10:10 -0800, srinivas pandruvada > > > > > > wrote: > > > > > > > Hi Pratyush, > > > > > > > > > > > > > > On Thu, 2022-12-22 at 11:39 +0100, Pratyush Yadav wrote: > > > > > > > > > > > > > > > > Hi Srinivas, > > > > > > > > > > > > > > > > On Wed, Dec 21 2022, srinivas pandruvada wrote: > > > > > > > > > On Wed, 2022-12-21 at 16:52 +0100, Pratyush Yadav > > > > > > > > > wrote: > > > > > > > > > > When a processor is brought offline and online > > > > > > > > > > again, > > > > > > > > > > it is > > > > > > > > > > unable to > > > > > > > > > > use Turbo mode because the _PSS table does not > > > > > > > > > > contain > > > > > > > > > > the > > > > > > > > > > whole > > > > > > > > > > turbo > > > > > > > > > > frequency range, but only +1 MHz above the max non- > > > > > > > > > > turbo > > > > > > > > > > frequency. > > > > > > > > > > This > > > > > > > > > > causes problems when ACPI processor driver tries to > > > > > > > > > > set > > > > > > > > > > frequency > > > > > > > > > > constraints. See patch 2 for more details. > > > > > > > > > > > > > > > > > I can reproduce on a Broadwell server platform. But not > > > > > > > on a > > > > > > > client > > > > > > > system with acpi_ppc usage. > > > > > > > > > > > > > > Need to check what change broke this. > > > > > > > > > > > > When PPC limits enforcement changed to PM QOS, this broke. > > > > > > Previously > > > > > > acpi_processor_get_platform_limit() was not enforcing any > > > > > > limits. > > > > > > It > > > > > > was just setting variable. So any update done after > > > > > > acpi_register_performance_state() call to pr->performance- > > > > > > > states[ppc].core_frequency, was effective. > > > > > > > > > > > > We don't really need to call > > > > > >         ret = freq_qos_update_request(&pr->perflib_req, > > > > > >                         pr->performance- > > > > > > > states[ppc].core_frequency > > > > > > * > > > > > > 1000); > > > > > > > > > > > > if the PPC is not changed. When PPC is changed, this gets > > > > > > called > > > > > > again, > > > > > > so then we can call the above function to update cpufreq > > > > > > limit. > > > > > > > > > > > > The below change fixed for me. > > > > > > > > > > Right. > > > > I think, this is the only change you require to fix this. In > > > > addition > > > > set pr->performance_platform_limit = 0 in > > > > acpi_processor_unregister_performance(). > > > > > > Not really, because if the limit is set to a lower frequency and > > > then > > > reset to _PSS[0], it needs to be set back to "no limit". > > > > > > > If PPC becomes 0 again after ppc > 0 during dynamic PPC change, pr- > > > performance_platform_limit will not match current PPC, so will > > > set to > > PPC 0 performance ( which is already patched by driver after return > > from acpi_register_performance_state()). > > I see. > > > But fine, you can always set freq qos to FREQ_QOS_MAX_DEFAULT_VALUE > > for > > PPC 0 as you are doing in your patch. > > I think that using the "no limit" value to represent the "no limit" > condition makes sense. Agree. > > Also, I'm wondering if the patching of states[0].core_frequency will > still be necessary after this change. I don't think so. We can remove the patching.