From owner-svn-src-head@freebsd.org Tue May 9 12:40:30 2017 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id D8EF0D64822; Tue, 9 May 2017 12:40:30 +0000 (UTC) (envelope-from melounmichal@gmail.com) Received: from mail-wr0-x243.google.com (mail-wr0-x243.google.com [IPv6:2a00:1450:400c:c0c::243]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 5D1DD1811; Tue, 9 May 2017 12:40:30 +0000 (UTC) (envelope-from melounmichal@gmail.com) Received: by mail-wr0-x243.google.com with SMTP id w50so13423733wrc.0; Tue, 09 May 2017 05:40:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:reply-to:subject:to:cc:references:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=8XhwPgEAjDqG+SMjMMGRMzj+7VkuQFdXQP/t2ClmDXU=; b=GAjh88nuZoPOx040vvW/9gsFuoaTnobB1b1qcPtDl2LUN7Mu0Hs3fn5pXe/m2U5AbP wTALv3n2JW5UiDT3L1MWZFlJO+pWBqgGUGJSXzgfdBydqx0QYKrRBTcLq4GJC9++r6A4 RQZ5DkQkA7JhDC7eIilxiVK24mzWhth9T4ULYg/sxgG+7wrRyBkw3rOfpZfjuW6LNtuW +2EIYrqoorqcW0TxgYUrDgkjCAm4tFpVMWcFQYdNrqCn3066XX1A0XosibX/uPNY16LY SBmrPY1GhG9XgZtsZMQyy87a7SWmKdibOIyq7pq4lBcDBrKt6v8T65q30gyZSXOznWr3 m/qA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:reply-to:subject:to:cc:references :message-id:date:user-agent:mime-version:in-reply-to :content-transfer-encoding:content-language; bh=8XhwPgEAjDqG+SMjMMGRMzj+7VkuQFdXQP/t2ClmDXU=; b=tP6CHqG73dVvB62uy7MYXoEzCp2zUxAeQnIJA7GDPya0yr7+I51gvIITqP04rSADqt o3dWgMGpPPESaZUl2BiCTmiJ4QfbV11LACNVWfZtfHwquBmIqD/4GwyqK6aDV914P5Qg CF76/I96HtQaj8o40zy3aVkDYyB5X0Aboo0vvKk7zS+1Niveos2Rv0ANHLLv9GXN/4Ug z6OqKAilouw8mdbrbhvj7dzbyBR2bq++70ltyT2WLygkE9KLTTFD3RG8ASe1TJzA7sm9 8XHvaeIMQ6YH7cn2FKoQpYfk5h7i71FQWS78hk6d8Ce7BJOfjduN0Dfa2+rqik5MWe2S w4Cg== X-Gm-Message-State: AODbwcCkjZxSm2t4s4VaW57JqrLiGuE7IEzltd9ajGBNl1lVzsrgJ3eg yH7/2pr4N8XovQLOPbkRpA== X-Received: by 10.28.58.16 with SMTP id h16mr1639380wma.131.1494333628431; Tue, 09 May 2017 05:40:28 -0700 (PDT) Received: from [88.208.79.100] (halouny.humusoft.cz. [88.208.79.100]) by smtp.gmail.com with ESMTPSA id g25sm23515693wra.1.2017.05.09.05.40.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 May 2017 05:40:27 -0700 (PDT) From: Michal Meloun X-Google-Original-From: Michal Meloun Reply-To: mmel@freebsd.org Subject: Re: svn commit: r318021 - in head/sys/arm: arm include To: Andrew Turner Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org References: <201705091105.v49B5WAp097952@repo.freebsd.org> <85745E3A-3260-43C7-B134-85BFED786D55@fubar.geek.nz> Message-ID: <8fe20c26-3c0c-98ce-227b-740491253047@freebsd.org> Date: Tue, 9 May 2017 14:40:29 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.1.0 MIME-Version: 1.0 In-Reply-To: <85745E3A-3260-43C7-B134-85BFED786D55@fubar.geek.nz> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 May 2017 12:40:31 -0000 On 09.05.2017 13:34, Andrew Turner wrote: >> On 9 May 2017, at 12:05, Michal Meloun wrote: >> >> Author: mmel >> Date: Tue May 9 11:05:32 2017 >> New Revision: 318021 >> URL: https://svnweb.freebsd.org/changeset/base/318021 >> >> Log: >> Introduce pmap_remap_vm_attr(), >> it allows to remap one VM memattr class to another. >> >> This function is intent to be used as workaround for various SoC bugs, >> mainly access ordering/sequencing related bugs in crossbar fabric. > This seems quite heavy handed to change the attribute for all memory of a given type. Yes, exactly. See comment in D10218 - /* * Workaround for Marvell Armada38X family HW issue * between Cortex-A9 CPUs and on-chip devices that may * cause hang on heavy load. * To avoid that, map all registers including PCIe IO * as strongly ordered instead of device memory. */ > Other architectures have pmap_change_attr to change the attribute on a specific range of memory. Right. Problem is that I don't known any method how we can change memory attribute for live memory in SMP system, without hitting undefined behavior. Michal