From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH]: Clean up of __alloc_pages From: Rohit Seth In-Reply-To: References: <20051001120023.A10250@unix-os.sc.intel.com> <1128358558.8472.13.camel@akash.sc.intel.com> Content-Type: text/plain Date: Mon, 03 Oct 2005 10:48:33 -0700 Message-Id: <1128361714.8472.44.camel@akash.sc.intel.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: akpm@osdl.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Mon, 2005-10-03 at 09:57 -0700, Christoph Lameter wrote: > On Mon, 3 Oct 2005, Rohit Seth wrote: > > > > Seems that this removes the logic intended to prefer local > > > allocations over remote pages present in the existing alloc_pages? There > > > is the danger that this modification will lead to the allocation of remote > > > pages even if local pages are available. Thus reducing performance. > > Good catch. I will up level the cpuset check in buffered_rmqueue rather > > then doing it in get_page_from_freelist. That should retain the current > > preferences for local pages. > > This is not only the cpuset check. If there is memory available in an > earlier zone then it needs to be taken regardless of later pcp's > the zonelist containing pages. Otherwise we did not take the pages nearest > to the requested node. > Ah. Okay. > > > I would suggest to just check the first zone's pcp instead of all zones. > > > > > > > Na. This for most cases will be ZONE_DMA pcp list having nothing much > > most of the time. And picking any other zone randomly will be exposed > > to faulty behavior. > > Maybe only check the first node? > I think conceptually this ask for a new flag __GFP_NODEONLY that indicate allocations to come from current node only. This definitely though means I will need to separate out the allocation from pcp patch (as Nick suggested earlier). -rohit -- 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