From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f177.google.com (mail-pf0-f177.google.com [209.85.192.177]) by kanga.kvack.org (Postfix) with ESMTP id AD9326B0005 for ; Fri, 22 Jan 2016 04:17:16 -0500 (EST) Received: by mail-pf0-f177.google.com with SMTP id q63so40299440pfb.1 for ; Fri, 22 Jan 2016 01:17:16 -0800 (PST) Received: from mail-pa0-x22f.google.com (mail-pa0-x22f.google.com. [2607:f8b0:400e:c03::22f]) by mx.google.com with ESMTPS id xk9si8396326pab.38.2016.01.22.01.17.15 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 22 Jan 2016 01:17:16 -0800 (PST) Received: by mail-pa0-x22f.google.com with SMTP id uo6so39471786pac.1 for ; Fri, 22 Jan 2016 01:17:15 -0800 (PST) Date: Fri, 22 Jan 2016 20:17:07 +1100 From: Balbir Singh Subject: Re: [LSF/MM ATTEND] 2016: Requests to attend MM-summit Message-ID: <20160122201707.1271a279@cotter.ozlabs.ibm.com> In-Reply-To: <87k2n2usyf.fsf@linux.vnet.ibm.com> References: <87k2n2usyf.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Aneesh Kumar K.V" Cc: lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org On Fri, 22 Jan 2016 10:11:12 +0530 "Aneesh Kumar K.V" wrote: > Hi, > > I would like to attend LSF/MM this year (2016). > > My main interest is in MM related topics although I am also interested > in the btrfs status discussion (particularly related to subpage size block > size topic), if we are having one. Most of my recent work in the kernel is > related to adding ppc64 support for different MM features. My current focus > is on adding Linux support for the new radix MMU model of Power9. > > Topics of interest include: > > * CMA allocator issues: > (1) order zero allocation failures: > We are observing order zero non-movable allocation failures in kernel > with CMA configured. We don't start a reclaim because our free memory check > does not consider free_cma. Hence the reclaim code assume we have enough free > pages. Joonsoo Kim tried to fix this with his ZOME_CMA patches. I would > like to discuss the challenges in getting this merged upstream. > https://lkml.org/lkml/2015/2/12/95 (ZONE_CMA) > > Others needed for the discussion: > Joonsoo Kim > > (2) CMA allocation failures due to pinned pages in the region: > We allow only movable allocation from the CMA region to enable us > to migrate those pages later when we get a CMA allocation request. But > if we pin those movable pages, we will fail the migration which can result > in CMA allocation failure. One such report can be found here. > http://article.gmane.org/gmane.linux.kernel.mm/136738 > > Peter Zijlstra's VM_PINNED patch series should help in fixing the issue. I would > like to discuss what needs to be done to get this patch series merged upstream > https://lkml.org/lkml/2014/5/26/345 (VM_PINNED) > > Others needed for the discussion: > Peter Zijlstra +1 I agree CMA design is a concern. I also noticed that today all CMA pages come from one node. On a NUMA box you'll see cross traffic going to that region - although from kernel only text. It should be discussed at the summit and Aneesh would be a good representative Balbir Singh. -- 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