From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-we0-f170.google.com (mail-we0-f170.google.com [74.125.82.170]) by kanga.kvack.org (Postfix) with ESMTP id AE2E06B0035 for ; Fri, 30 May 2014 17:44:35 -0400 (EDT) Received: by mail-we0-f170.google.com with SMTP id u57so2692016wes.15 for ; Fri, 30 May 2014 14:44:35 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTP id eo20si7511089wid.19.2014.05.30.14.44.32 for ; Fri, 30 May 2014 14:44:33 -0700 (PDT) Date: Fri, 30 May 2014 18:43:45 -0300 From: Marcelo Tosatti Subject: Re: [PATCH] page_alloc: skip cpuset enforcement for lower zone allocations (v4) Message-ID: <20140530214344.GA14720@amt.cnet> References: <20140523193706.GA22854@amt.cnet> <20140526185344.GA19976@amt.cnet> <53858A06.8080507@huawei.com> <20140528224324.GA1132@amt.cnet> <20140529184303.GA20571@amt.cnet> <20140529161253.73ff978f723972f503123fe8@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Andrew Morton , David Rientjes , Li Zefan , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Lai Jiangshan , Mel Gorman , Tejun Heo , Andi Kleen On Fri, May 30, 2014 at 08:48:41AM -0500, Christoph Lameter wrote: > On Thu, 29 May 2014, Andrew Morton wrote: > > > > > > > if (!nodemask && gfp_zone(gfp_mask) < policy_zone) > > > nodemask = &node_states[N_ONLINE]; > > > > OK, thanks, I made the patch go away for now. > > > > And another issue is that the policy_zone may be highmem on 32 bit > platforms which will result in ZONE_NORMAL to be exempted. > > policy zone can actually even be ZONE_DMA for some platforms. The > check would not be useful at all on those. > > Ignoring the containing cpuset only makes sense for GFP_DMA32 on > 64 bit platforms and for GFP_DMA on platforms where there is an actual > difference in the address spaces supported by GFP_DMA (such as x86). > > Generally I think this is only useful for platforms that attempt to > support legacy devices only able to DMA to a portion of the memory address > space and that at the same time support NUMA for large address spaces. > This is a contradiction on the one hand this is a high end system and on > the other hand it attempts to support crippled DMA devices? OK we will handle this in userspace. -- 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