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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 27EB9C433DF for ; Mon, 18 May 2020 11:26:09 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id ECCE9206D4 for ; Mon, 18 May 2020 11:26:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="V4KkwnxM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECCE9206D4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.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=cL94JBkyAU/rYVHApvvy2EyEeiytERZZtp/cynVcDdM=; b=V4KkwnxMzmZba5 NfESK+uGw0uPdYXP8k4e6IsDiweoMH7wYmNCxlrjBtEuK3vVz2s2K8PK1O2ZZRrINtbN9+BHCDqAR svb3Tn0gneJS32CGFAe7E8wYmihPKwQVLB8V1TgYg4poVdccBA8jkHMLTPkzlCxqtkmZ3X70GS1hB dYOkshoO2bazOLUdtGvOq6ktn00mmT0npBOfXBE9y3ycRTFD6V7+vlhHIrtY14iQGy8NwFV1RSUzf XyFA0+ihLCyl1af5MNKOM1kk55D+GmgCPQ5j84oiqIhTL0qvnFmgUKd/ykdectZ5rI2KM8rR/ylwq RSZFoGUPSj/Hync/BPPw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jaduK-0005b8-D1; Mon, 18 May 2020 11:26:08 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jaduH-0005aC-Fy for linux-arm-kernel@lists.infradead.org; Mon, 18 May 2020 11:26:06 +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 06174106F; Mon, 18 May 2020 04:26:02 -0700 (PDT) Received: from [10.57.27.185] (unknown [10.57.27.185]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 194B13F52E; Mon, 18 May 2020 04:25:59 -0700 (PDT) Subject: Re: [PATCH v4 24/26] arm64: mte: Introduce early param to disable MTE support To: Catalin Marinas , linux-arm-kernel@lists.infradead.org References: <20200515171612.1020-1-catalin.marinas@arm.com> <20200515171612.1020-25-catalin.marinas@arm.com> From: Vladimir Murzin Message-ID: Date: Mon, 18 May 2020 12:26:30 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20200515171612.1020-25-catalin.marinas@arm.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200518_042605_575864_91B94FA6 X-CRM114-Status: GOOD ( 16.23 ) 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: linux-arch@vger.kernel.org, Will Deacon , Szabolcs Nagy , Andrey Konovalov , Kevin Brodsky , linux-mm@kvack.org, Vincenzo Frascino , Peter Collingbourne , Dave P Martin Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 5/15/20 6:16 PM, Catalin Marinas wrote: > For performance analysis it may be desirable to disable MTE altogether > via an early param. Introduce arm64.mte_disable and, if true, filter out > the sanitised ID_AA64PFR1_EL1.MTE field to avoid exposing the HWCAP to > user. > > Signed-off-by: Catalin Marinas > Cc: Will Deacon > --- > > Notes: > New in v4. > > Documentation/admin-guide/kernel-parameters.txt | 4 ++++ > arch/arm64/kernel/cpufeature.c | 11 +++++++++++ > 2 files changed, 15 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index f2a93c8679e8..7436e7462b85 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -373,6 +373,10 @@ > arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards > Format: ,, > > + arm64.mte_disable= > + [ARM64] Disable Linux support for the Memory > + Tagging Extension (both user and in-kernel). > + Should it really to take parameter (on/off/true/false)? It may lead to expectation that arm64.mte_disable=false should enable MT and, yes, double negatives make it look ugly, so if we do need parameter, can it be arm64.mte=on/off/true/false? Cheers Vladimir _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel