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 X-Spam-Level: X-Spam-Status: No, score=-13.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8346C433DF for ; Wed, 26 Aug 2020 08:39:30 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 4343A20707 for ; Wed, 26 Aug 2020 08:39:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4343A20707 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4Bbzmv6z6czDqX2 for ; Wed, 26 Aug 2020 18:39:27 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=csgroup.eu (client-ip=93.17.236.30; helo=pegase1.c-s.fr; envelope-from=christophe.leroy@csgroup.eu; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Bbzkt2yN3zDqVx for ; Wed, 26 Aug 2020 18:37:38 +1000 (AEST) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4Bbzkh37FWz9tyjT; Wed, 26 Aug 2020 10:37:32 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id F7HkzAmN4Nfz; Wed, 26 Aug 2020 10:37:32 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4Bbzkh2GV1z9tyjS; Wed, 26 Aug 2020 10:37:32 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 748488B82E; Wed, 26 Aug 2020 10:37:33 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id zkDSwkkPY4fl; Wed, 26 Aug 2020 10:37:33 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id B61B58B835; Wed, 26 Aug 2020 10:37:32 +0200 (CEST) Subject: Re: [PATCH] Revert "powerpc/powernv/idle: Replace CPU feature check with PVR check" To: Pratik Rajesh Sampat , linuxppc-dev@lists.ozlabs.org, mpe@ellerman.id.au, npiggin@gmail.com, mikey@neuling.org, ego@linux.vnet.ibm.com, svaidy@linux.ibm.com, linux-kernel@vger.kernel.org, pratik.r.sampat@gmail.com References: <20200826082918.89306-1-psampat@linux.ibm.com> From: Christophe Leroy Message-ID: <1fb7fcef-a39d-d36e-35d5-021a5c9ea82c@csgroup.eu> Date: Wed, 26 Aug 2020 10:37:13 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200826082918.89306-1-psampat@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Le 26/08/2020 à 10:29, Pratik Rajesh Sampat a écrit : > Cpuidle stop state implementation has minor optimizations for P10 > where hardware preserves more SPR registers compared to P9. > The current P9 driver works for P10, although does few extra > save-restores. P9 driver can provide the required power management > features like SMT thread folding and core level power savings > on a P10 platform. > > Until the P10 stop driver is available, revert the commit which > allows for only P9 systems to utilize cpuidle and blocks all > idle stop states for P10. > Cpu idle states are enabled and tested on the P10 platform > with this fix. > > This reverts commit 8747bf36f312356f8a295a0c39ff092d65ce75ae. > > Fixes: 8747bf36f312 ("powerpc/powernv/idle: Replace CPU feature check with PVR check") > Signed-off-by: Pratik Rajesh Sampat > --- > @mpe: This revert would resolve a staging issue wherein the P10 stop > driver is not yet ready while cpuidle stop states need not be blocked > on 5.9 for Power10 systems which could cause SMT folding related > performance issues. > > The P10 stop driver is in the works here: > https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-August/216773.html > > arch/powerpc/platforms/powernv/idle.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c > index 77513a80cef9..345ab062b21a 100644 > --- a/arch/powerpc/platforms/powernv/idle.c > +++ b/arch/powerpc/platforms/powernv/idle.c > @@ -1223,7 +1223,7 @@ static void __init pnv_probe_idle_states(void) > return; > } > > - if (pvr_version_is(PVR_POWER9)) > + if (cpu_has_feature(CPU_FTR_ARCH_300)) Why not something like: if (pvr_version_is(PVR_POWER9) || pvr_version_is(PVR_POWER10)) pnv_power9_idle_init(); > pnv_power9_idle_init(); > > for (i = 0; i < nr_pnv_idle_states; i++) > Christophe