Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752013AbbDYCc6 (ORCPT ); Fri, 24 Apr 2015 22:32:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42784 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750931AbbDYCc5 (ORCPT ); Fri, 24 Apr 2015 22:32:57 -0400 Message-ID: <553AFCC1.5070502@redhat.com> Date: Fri, 24 Apr 2015 22:32:33 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org CC: jglisse@redhat.com, mgorman@suse.de, aarcange@redhat.com, airlied@redhat.com, benh@kernel.crashing.org, aneesh.kumar@linux.vnet.ibm.com, Cameron Buschardt , Mark Hairgrove , Geoffrey Gerfin , John McKenna , akpm@linux-foundation.org Subject: Re: Interacting with coherent memory on external devices References: <20150421214445.GA29093@linux.vnet.ibm.com> In-Reply-To: <20150421214445.GA29093@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1287 Lines: 34 On 04/21/2015 05:44 PM, Paul E. McKenney wrote: > AUTONUMA > > The Linux kernel's autonuma facility supports migrating both > memory and processes to promote NUMA memory locality. It was > accepted into 3.13 and is available in RHEL 7.0 and SLES 12. > It is enabled by the Kconfig variable CONFIG_NUMA_BALANCING. > > This approach uses a kernel thread "knuma_scand" that periodically > marks pages inaccessible. The page-fault handler notes any > mismatches between the NUMA node that the process is running on > and the NUMA node on which the page resides. Minor nit: marking pages inaccessible is done from task_work nowadays, there no longer is a kernel thread. > The result would be that the kernel would allocate only migratable > pages within the CCAD device's memory, and even then only if > memory was otherwise exhausted. Does it make sense to allocate the device's page tables in memory belonging to the device? Is this a necessary thing with some devices? Jerome's HMM comes to mind... -- All rights reversed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/