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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 5CDFAC433DB for ; Tue, 9 Feb 2021 10:38:15 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 E370564E4B for ; Tue, 9 Feb 2021 10:38:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E370564E4B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=s8QZvgD1upxs2rc6rQ+tjZTGY66wOetIqDTqMxMZZxA=; b=mQg63a0550Oj+k8GHUjifCVO7 0P3c2aOSbZsbEcFleDFzERzfPFVwwy7WCKauMpUAAcvY31wGq4/l2QbFnfBCn1AE3jnXAjnDZBn7C g+E/qCHpO5Q0o0kt3FZutKyce7HzD2+5hQj5u/1XTtXsKu+7uaSec452j2pOonnY7TAE9nqeLz2bx MRCaWWz3H8qbQTADLUCLqtCqiMXa79oFRvZWNcQ9g64kY/jqzDNIqOgeELL/wIJ+ohvcuAy7ddM6A 7q3QYn5loMdKEKU7Aecq3m05SdbSejQ7uVJKigF1dg9z6VZPfVBDXvOctwPWLoF18pNP+zh07jM9+ lXYiNeSXQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l9QOM-0000e4-0f; Tue, 09 Feb 2021 10:37:10 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l9QOI-0000dF-5f for linux-arm-kernel@lists.infradead.org; Tue, 09 Feb 2021 10:37:07 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 060BF101E; Tue, 9 Feb 2021 02:37:04 -0800 (PST) Received: from [10.37.8.18] (unknown [10.37.8.18]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1FE4D3F73B; Tue, 9 Feb 2021 02:37:00 -0800 (PST) Subject: Re: [PATCH v12 6/7] arm64: mte: Save/Restore TFSR_EL1 during suspend To: Lorenzo Pieralisi References: <20210208165617.9977-1-vincenzo.frascino@arm.com> <20210208165617.9977-7-vincenzo.frascino@arm.com> <20210208185635.GA13187@e121166-lin.cambridge.arm.com> From: Vincenzo Frascino Message-ID: Date: Tue, 9 Feb 2021 10:41:03 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210208185635.GA13187@e121166-lin.cambridge.arm.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210209_053706_323455_17A0265B X-CRM114-Status: GOOD ( 14.17 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Branislav Rankov , Marco Elver , Catalin Marinas , Evgenii Stepanov , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, Alexander Potapenko , Dmitry Vyukov , Andrey Konovalov , Andrey Ryabinin , Andrew Morton , Will Deacon , linux-arm-kernel@lists.infradead.org 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 Hi Lorenzo, thank you for your review. On 2/8/21 6:56 PM, Lorenzo Pieralisi wrote: >> u64 gcr_kernel_excl __ro_after_init; >> >> +static u64 mte_suspend_tfsr_el1; > IIUC you need this per-CPU (core loses context on suspend-to-RAM but also > CPUidle, S2R is single threaded but CPUidle runs on every core idle > thread). > > Unless you sync/report it on enter/exit (please note: I am not familiar > with MTE so it is just a, perhaps silly, suggestion to avoid > saving/restoring it). > I thought about making it per cpu, but I concluded that since it is an asynchronous tag fault it wasn't necessary. But thinking at it from the statistical point of view what you are saying is completely right, because we might end up in scenario in which we report the fault on multiple cores when it happens on one or in a scenario in which we do not report the potential fault at all. I am going to update my code accordingly in the next version. Thanks! > Lorenzo > -- Regards, Vincenzo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel