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=-10.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,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 29F34C48BE6 for ; Wed, 16 Jun 2021 09:29:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B336B611CA for ; Wed, 16 Jun 2021 09:29:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B336B611CA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 475C36B0070; Wed, 16 Jun 2021 05:29:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4260C6B0071; Wed, 16 Jun 2021 05:29:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2C6C06B0072; Wed, 16 Jun 2021 05:29:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0115.hostedemail.com [216.40.44.115]) by kanga.kvack.org (Postfix) with ESMTP id EC7136B0070 for ; Wed, 16 Jun 2021 05:29:00 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 6BA60180AD806 for ; Wed, 16 Jun 2021 09:29:00 +0000 (UTC) X-FDA: 78259062840.29.0E8723B Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) by imf17.hostedemail.com (Postfix) with ESMTP id 8936E40002E4 for ; Wed, 16 Jun 2021 09:28:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Zijywzcu+CRpy/ste35r5eGAhkZFfZgYscvI8y8dbwg=; b=DgHkYvIY5f4HrojOxk+6Los3F 6s/7F4MufGeVJsyeuJXSDhRMhHEPVB/RvnxGVR8JY1QZNg3LnxYQfSyKS2z7LBpE/p8bucZ248GKG d/ZVFelm142vbbhS62giUFbmD+3yZn7B9yPU4XsxilNobujAMVQBGyXF9wOJJrLXoQy0iG8tZqC/h MmNhfyAQok6XRUO/QrZg7bE4O3F/dY9E0HaYmVcw5XxsuIWPRl7R5Adw8jYdDbcATtOhchsv1R+A6 M4DR6+szwRaqzS1Z8Ik7A9dTHcB06wC3j2+6j6jQhfJC/DlprdfxGwCYnoeTJ1j5u2vpWVB/Zqt7Q wpFWYHLlw==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:45054) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ltRqr-0006yX-NZ; Wed, 16 Jun 2021 10:28:49 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1ltRql-0005tq-Ng; Wed, 16 Jun 2021 10:28:43 +0100 Date: Wed, 16 Jun 2021 10:28:43 +0100 From: "Russell King (Oracle)" To: Andy Lutomirski Cc: x86@kernel.org, Dave Hansen , LKML , linux-mm@kvack.org, Andrew Morton , Mathieu Desnoyers , Nicholas Piggin , Peter Zijlstra , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 7/8] membarrier: Remove arm (32) support for SYNC_CORE Message-ID: <20210616092843.GZ22278@shell.armlinux.org.uk> References: <2142129092ff9aa00e600c42a26c4015b7f5ceec.1623813516.git.luto@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2142129092ff9aa00e600c42a26c4015b7f5ceec.1623813516.git.luto@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 8936E40002E4 X-Stat-Signature: hanizgy8drjqe5868nbgdsqdbajjm81d Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=armlinux.org.uk header.s=pandora-2019 header.b=DgHkYvIY; dmarc=pass (policy=none) header.from=armlinux.org.uk; spf=none (imf17.hostedemail.com: domain of linux@armlinux.org.uk has no SPF policy when checking 78.32.30.218) smtp.mailfrom=linux@armlinux.org.uk X-HE-Tag: 1623835732-551397 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000102, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jun 15, 2021 at 08:21:12PM -0700, Andy Lutomirski wrote: > On arm32, the only way to safely flush icache from usermode is to call > cacheflush(2). This also handles any required pipeline flushes, so > membarrier's SYNC_CORE feature is useless on arm. Remove it. Yay! About time too. Acked-by: Russell King (Oracle) -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!