From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id A65B26B0033 for ; Thu, 16 Nov 2017 17:41:41 -0500 (EST) Received: by mail-wm0-f71.google.com with SMTP id x63so806129wmf.2 for ; Thu, 16 Nov 2017 14:41:41 -0800 (PST) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id b193sor701751wmd.5.2017.11.16.14.41.40 for (Google Transport Security); Thu, 16 Nov 2017 14:41:40 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20171116212904.GA4823@redhat.com> References: <20170926161635.GA3216@redhat.com> <0d7273c3-181c-6d68-3c5f-fa518e782374@huawei.com> <20170930224927.GC6775@redhat.com> <20171012153721.GA2986@redhat.com> <20171116024425.GC2934@redhat.com> <20171116212904.GA4823@redhat.com> From: chetan L Date: Thu, 16 Nov 2017 14:41:39 -0800 Message-ID: Subject: Re: [PATCH 0/6] Cache coherent device memory (CDM) with HMM v5 Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Jerome Glisse Cc: Bob Liu , David Nellans , John Hubbard , Balbir Singh , "linux-kernel@vger.kernel.org" , Michal Hocko , Linux MM , Dan Williams , Andrew Morton , linux-accelerators@lists.ozlabs.org On Thu, Nov 16, 2017 at 1:29 PM, Jerome Glisse wrote: > > For the NUMA discussion this is related to CPU less node ie not wanting > to add any more CPU less node (node with only memory) and they are other > aspect too. For instance you do not necessarily have good informations > from the device to know if a page is access a lot by the device (this > kind of information is often only accessible by the device driver). Thus @Jerome - one comment w.r.t 'do not necessarily have good info on device access'. So you could be assuming a few things here :). CCIX extends the CPU complex's coherency domain(it is now a single/unified coherency domain). The CCIX-EP (lets say an accelerator/XPU or a NIC or a combo) is now a true peer w.r.t the host-numa-node(s) (aka 1st class citizen). I don't know how much info was revealed at the latest ARM techcon where CCIX was presented. So I cannot divulge any further details until I see that slide deck. However, you can safely assume that the host will have *all* the info w.r.t the device-access and vice-versa. Chetan -- 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