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 mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B31AC433F5 for ; Wed, 23 Feb 2022 15:28:50 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id E0EFC4C5E9; Wed, 23 Feb 2022 10:28:49 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 4ad-7HwO0hwT; Wed, 23 Feb 2022 10:28:48 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 741324C5E7; Wed, 23 Feb 2022 10:28:48 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 1D57C4C5E5 for ; Wed, 23 Feb 2022 10:28:47 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id wx1474A8vWFB for ; Wed, 23 Feb 2022 10:28:45 -0500 (EST) Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id B43144C5E4 for ; Wed, 23 Feb 2022 10:28:45 -0500 (EST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id DCD77B82036; Wed, 23 Feb 2022 15:28:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B21BC340E7; Wed, 23 Feb 2022 15:28:39 +0000 (UTC) Date: Wed, 23 Feb 2022 15:28:35 +0000 From: Catalin Marinas To: Mark Brown Subject: Re: [PATCH v11 24/40] arm64/sme: Disable streaming mode and ZA when flushing CPU state Message-ID: References: <20220207152109.197566-1-broonie@kernel.org> <20220207152109.197566-25-broonie@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220207152109.197566-25-broonie@kernel.org> Cc: Basant Kumar Dwivedi , Will Deacon , Luis Machado , Szabolcs Nagy , Marc Zyngier , Shuah Khan , linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, Alan Hayward , Shuah Khan , kvmarm@lists.cs.columbia.edu, Salil Akerkar X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Mon, Feb 07, 2022 at 03:20:53PM +0000, Mark Brown wrote: > Both streaming mode and ZA may increase power consumption when they are > enabled and streaming mode makes many FPSIMD and SVE instructions undefined > which will cause problems for any kernel mode floating point so disable > both when we flush the CPU state. This covers both kernel_neon_begin() and > idle and after flushing the state a reload is always required anyway. > > Signed-off-by: Mark Brown Reviewed-by: Catalin Marinas _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm 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 8645CC433EF for ; Wed, 23 Feb 2022 15:28:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232535AbiBWP3R (ORCPT ); Wed, 23 Feb 2022 10:29:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242071AbiBWP3Q (ORCPT ); Wed, 23 Feb 2022 10:29:16 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 86D72657AB for ; Wed, 23 Feb 2022 07:28:45 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E75B3B82077 for ; Wed, 23 Feb 2022 15:28:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B21BC340E7; Wed, 23 Feb 2022 15:28:39 +0000 (UTC) Date: Wed, 23 Feb 2022 15:28:35 +0000 From: Catalin Marinas To: Mark Brown Cc: Will Deacon , Marc Zyngier , Shuah Khan , Shuah Khan , Alan Hayward , Luis Machado , Salil Akerkar , Basant Kumar Dwivedi , Szabolcs Nagy , James Morse , Alexandru Elisei , Suzuki K Poulose , linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, kvmarm@lists.cs.columbia.edu Subject: Re: [PATCH v11 24/40] arm64/sme: Disable streaming mode and ZA when flushing CPU state Message-ID: References: <20220207152109.197566-1-broonie@kernel.org> <20220207152109.197566-25-broonie@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220207152109.197566-25-broonie@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Mon, Feb 07, 2022 at 03:20:53PM +0000, Mark Brown wrote: > Both streaming mode and ZA may increase power consumption when they are > enabled and streaming mode makes many FPSIMD and SVE instructions undefined > which will cause problems for any kernel mode floating point so disable > both when we flush the CPU state. This covers both kernel_neon_begin() and > idle and after flushing the state a reload is always required anyway. > > Signed-off-by: Mark Brown Reviewed-by: Catalin Marinas 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 0C866C433F5 for ; Wed, 23 Feb 2022 15:29:57 +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=dfOr0sjT5aeZHwwPn5Mvm0Kg64v8AnFUaI0UZnmraxg=; b=uygh/aOGXsJFBq MKGZs9rEmgh4TyP2eKDHemk7Mxs+np7h3N36kW4IfFefUhZZFXdPmG0Olo2VNGb9p69KVen9V0jJ6 g8I3Y5thoz6mmKZuLMhj0lwr7ezc3avtr98tPrqMM/w9VxblJzyPXZZSJ/n/+dz0y7NSRPRfmDant mqXvX+EZ/scVTXuzLz3pK7cUNsDg1Sd4Nw2IS7xxOCxrvDxr3dWhnUiQrSfHDFoiUQKzdxhROVwAy Nnk9LjQ4/l5ndRENBS2I1lKcvPb74fr2NPEkun/mujus/s0mlt90QT6WccoZ2JDPbons++CCY9PTG FzNk40j6/GJ75NOvb8xg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nMtZR-00F1gT-5e; Wed, 23 Feb 2022 15:28:49 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nMtZN-00F1ex-C3 for linux-arm-kernel@lists.infradead.org; Wed, 23 Feb 2022 15:28:46 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id DCD77B82036; Wed, 23 Feb 2022 15:28:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B21BC340E7; Wed, 23 Feb 2022 15:28:39 +0000 (UTC) Date: Wed, 23 Feb 2022 15:28:35 +0000 From: Catalin Marinas To: Mark Brown Cc: Will Deacon , Marc Zyngier , Shuah Khan , Shuah Khan , Alan Hayward , Luis Machado , Salil Akerkar , Basant Kumar Dwivedi , Szabolcs Nagy , James Morse , Alexandru Elisei , Suzuki K Poulose , linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, kvmarm@lists.cs.columbia.edu Subject: Re: [PATCH v11 24/40] arm64/sme: Disable streaming mode and ZA when flushing CPU state Message-ID: References: <20220207152109.197566-1-broonie@kernel.org> <20220207152109.197566-25-broonie@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220207152109.197566-25-broonie@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220223_072845_597772_9EFE0D63 X-CRM114-Status: UNSURE ( 9.72 ) X-CRM114-Notice: Please train this message. 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 On Mon, Feb 07, 2022 at 03:20:53PM +0000, Mark Brown wrote: > Both streaming mode and ZA may increase power consumption when they are > enabled and streaming mode makes many FPSIMD and SVE instructions undefined > which will cause problems for any kernel mode floating point so disable > both when we flush the CPU state. This covers both kernel_neon_begin() and > idle and after flushing the state a reload is always required anyway. > > Signed-off-by: Mark Brown Reviewed-by: Catalin Marinas _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel