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[23.128.96.18]) by mx.google.com with ESMTP id j3si1717109ejv.180.2021.06.16.02.30.14; Wed, 16 Jun 2021 02:30:37 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=fail (test mode) header.i=@armlinux.org.uk header.s=pandora-2019 header.b=DgHkYvIY; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=armlinux.org.uk Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232106AbhFPJbH (ORCPT + 99 others); Wed, 16 Jun 2021 05:31:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231686AbhFPJbF (ORCPT ); Wed, 16 Jun 2021 05:31:05 -0400 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0171DC061574 for ; Wed, 16 Jun 2021 02:28:59 -0700 (PDT) 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) Sender: Russell King (Oracle) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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!