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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27F05C433F5 for ; Mon, 15 Nov 2021 11:27:06 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4C9EB61C32 for ; Mon, 15 Nov 2021 11:27:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4C9EB61C32 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=srcf.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.225812.390042 (Exim 4.92) (envelope-from ) id 1mma8D-0004fv-8X; Mon, 15 Nov 2021 11:26:37 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 225812.390042; Mon, 15 Nov 2021 11:26:37 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mma8D-0004fo-5H; Mon, 15 Nov 2021 11:26:37 +0000 Received: by outflank-mailman (input) for mailman id 225812; Mon, 15 Nov 2021 11:26:36 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mma8C-00043I-9K for xen-devel@lists.xenproject.org; Mon, 15 Nov 2021 11:26:36 +0000 Received: from ppsw-33.csi.cam.ac.uk (ppsw-33.csi.cam.ac.uk [131.111.8.133]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id e37f7629-4606-11ec-a9d2-d9f7a1cc8784; Mon, 15 Nov 2021 12:26:35 +0100 (CET) Received: from hades.srcf.societies.cam.ac.uk ([131.111.179.67]:46826) by ppsw-33.csi.cam.ac.uk (ppsw.cam.ac.uk [131.111.8.137]:25) with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) id 1mma8A-000HpV-g1 (Exim 4.95) (return-path ); Mon, 15 Nov 2021 11:26:34 +0000 Received: from [192.168.1.10] (host-92-12-61-86.as13285.net [92.12.61.86]) (Authenticated sender: amc96) by hades.srcf.societies.cam.ac.uk (Postfix) with ESMTPSA id 74FDE1FDB0; Mon, 15 Nov 2021 11:26:33 +0000 (GMT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: e37f7629-4606-11ec-a9d2-d9f7a1cc8784 X-Cam-AntiVirus: no malware found X-Cam-ScannerInfo: https://help.uis.cam.ac.uk/email-scanner-virus Subject: Re: [PATCH 3/3] x86/cpufreq: Drop opencoded CPUID handling from powernow To: Andrew Cooper , Xen-devel Cc: Jan Beulich , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , Wei Liu References: <20211112182818.30223-1-andrew.cooper3@citrix.com> <20211112182818.30223-4-andrew.cooper3@citrix.com> From: Andrew Cooper Message-ID: Date: Mon, 15 Nov 2021 11:26:32 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <20211112182818.30223-4-andrew.cooper3@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Language: en-GB On 12/11/2021 18:28, Andrew Cooper wrote: > Xen already collects CPUID.0x80000007.edx by default, meaning that we can > refer to per-cpu data directly. This also avoids the need IPI the onlining > CPU to identify whether Core Performance Boost is available. > > Signed-off-by: Andrew Cooper > --- > CC: Jan Beulich > CC: Roger Pau Monné > CC: Wei Liu > > I don't think the printk() is very helpful. I could be talked into retaining > it as a prink_once(), but (irrespective of cpufreq_verbose), it doesn't want > repeating on each CPU because it will either be all or none of them. I should note that the printk() is also false.  Nothing AFAICT synchronises the software turbo setting with hardware, until the next time set-turbo is called. ~Andrew