From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f44.google.com (mail-pa0-f44.google.com [209.85.220.44]) by kanga.kvack.org (Postfix) with ESMTP id B257C6B0038 for ; Mon, 21 Jul 2014 12:48:33 -0400 (EDT) Received: by mail-pa0-f44.google.com with SMTP id eu11so10209590pac.31 for ; Mon, 21 Jul 2014 09:48:33 -0700 (PDT) Received: from mail.zytor.com (terminus.zytor.com. [2001:1868:205::10]) by mx.google.com with ESMTPS id pm3si14781778pbb.64.2014.07.21.09.48.32 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 21 Jul 2014 09:48:32 -0700 (PDT) Message-ID: <53CD443A.6050804@zytor.com> Date: Mon, 21 Jul 2014 09:47:54 -0700 From: "H. Peter Anvin" MIME-Version: 1.0 Subject: Re: [RFC PATCH 0/11] Support Write-Through mapping on x86 References: <1405452884-25688-1-git-send-email-toshi.kani@hp.com> <53C58A69.3070207@zytor.com> <1405459404.28702.17.camel@misato.fc.hp.com> <03d059f5-b564-4530-9184-f91ca9d5c016@email.android.com> <1405546127.28702.85.camel@misato.fc.hp.com> <1405960298.30151.10.camel@misato.fc.hp.com> In-Reply-To: <1405960298.30151.10.camel@misato.fc.hp.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Toshi Kani , Konrad Rzeszutek Wilk Cc: tglx@linutronix.de, mingo@redhat.com, akpm@linux-foundation.org, arnd@arndb.de, plagnioj@jcrosoft.com, tomi.valkeinen@ti.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stefan.bader@canonical.com, luto@amacapital.net, airlied@gmail.com, bp@alien8.de On 07/21/2014 09:31 AM, Toshi Kani wrote: > Do you have any comments / suggestions for this approach? Approach to what, specifically? Keep in mind the PAT bit is different for large pages. This needs to be dealt with. I would also like a systematic way to deal with the fact that Xen (sigh) is stuck with a separate mapping system. I guess Linux could adopt the Xen mappings if that makes it easier, as long as that doesn't have a negative impact on native hardware -- we can possibly deal with some older chips not being optimal. However, my thinking has been to have a "reverse PAT" table in memory of memory types to encodings, both for regular and large pages. -hpa -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org