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 7DD3BC6FD18 for ; Wed, 29 Mar 2023 08:51:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231231AbjC2IvS (ORCPT ); Wed, 29 Mar 2023 04:51:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231278AbjC2IvH (ORCPT ); Wed, 29 Mar 2023 04:51:07 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 769A32733 for ; Wed, 29 Mar 2023 01:50:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=tu8D8sNJ5RV0W3AuFiycIVvG6n0AuLvN4txSs88tZ2E=; b=JiL4y62ZsZ1uxjqtNN9l2NqWSl wxFK6o6H4pWzhxVAQSDIXQNVDR9pMKbYaap0flqtbJgYCElstOCLDlAbI/ZULqUin+B0mfNOdsmnC 3toxNj3QkKeaWcpC6vNXDFdV2DWS2t6hEYTOD17aFe59/LrKoSStR1TqhbRQT+nxq86CY12GTC4oc duwoqyzBovddWn3KGZNYoRP2n2e76Up0t6hdkgKqJ9KJC07xYnxz7QWmkrWeFD50dq/1WxRcP93+g rYg2MU4TGWl4Ls13rt7Sz0OwILovO1FM6FZZtNF9EpmsgPnckV7RHBqy617mSrUTTWwwJK/eE8sej MEhM3vrA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1phRVg-006oAq-35; Wed, 29 Mar 2023 08:50:25 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 88D12300237; Wed, 29 Mar 2023 10:50:23 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 348AA262EE29D; Wed, 29 Mar 2023 10:50:23 +0200 (CEST) Date: Wed, 29 Mar 2023 10:50:23 +0200 From: Peter Zijlstra To: "Yang, WenYou" Cc: "Deucher, Alexander" , "Koenig, Christian" , "Pan, Xinhui" , "Quan, Evan" , "Limonciello, Mario" , bp@alien8.de, "jpoimboe@kernel.org" , "Phillips, Kim" , "tglx@linutronix.de" , "Yuan, Perry" , "Liang, Richard qi" , "Li, Ying" , "Liu, Kun" , "gpiccoli@igalia.com" , "amd-gfx@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v3 1/2] cpu/smt: add a notifier to notify the SMT changes Message-ID: <20230329085023.GO4253@hirez.programming.kicks-ass.net> References: <20230329015149.870132-1-WenYou.Yang@amd.com> <20230329015149.870132-2-WenYou.Yang@amd.com> <20230329071014.GC7701@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 29, 2023 at 07:23:29AM +0000, Yang, WenYou wrote: > [AMD Official Use Only - General] ^^^ that has no business being in a public email. > Hi Peter, > > Thank you for your review. > > The purpose of the patch set is to improve the performance when playing game for some AMD APUs with SMT enabled/disabled. > > When change the SMT state on the fly through " echo on/off > /sys/devices/system/cpu/smt/control", the kernel needs to send a message to notify PMFW to adjust a variable's value, which impacts the performance. When top posting I normally ignore the email. When not wrapping email I typically get cranky. You 'win' *3* 'I cannot use email' trophies in a singly try. Surely AMD has a HOWTO somewhere you can read? So what do you want to have happen when someone goes and manually offlines all the SMT siblings using /sys/devices/system/cpu/cpu*/online ? I'm thinking that wants the same PMFW (whatever the heck that is) notification change done, right? If the answer is "yes", then your patch does not meet the goals and is inadequate.