From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f53.google.com (mail-qg0-f53.google.com [209.85.192.53]) by kanga.kvack.org (Postfix) with ESMTP id 74E266B0035 for ; Thu, 21 Aug 2014 21:10:31 -0400 (EDT) Received: by mail-qg0-f53.google.com with SMTP id z60so6072028qgd.26 for ; Thu, 21 Aug 2014 18:10:31 -0700 (PDT) Received: from e7.ny.us.ibm.com (e7.ny.us.ibm.com. [32.97.182.137]) by mx.google.com with ESMTPS id y1si40622448qcr.8.2014.08.21.18.10.30 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 21 Aug 2014 18:10:30 -0700 (PDT) Received: from /spool/local by e7.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 21 Aug 2014 21:10:30 -0400 Received: from b01cxnp22036.gho.pok.ibm.com (b01cxnp22036.gho.pok.ibm.com [9.57.198.26]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 427C36E8048 for ; Thu, 21 Aug 2014 21:10:15 -0400 (EDT) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id s7M1AQwD36503716 for ; Fri, 22 Aug 2014 01:10:26 GMT Received: from d01av01.pok.ibm.com (localhost [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s7M1APNU026952 for ; Thu, 21 Aug 2014 21:10:26 -0400 Date: Thu, 21 Aug 2014 18:10:11 -0700 From: Nishanth Aravamudan Subject: Re: [RFC PATCH 0/4] Improve slab consumption with memoryless nodes Message-ID: <20140822011011.GF13999@linux.vnet.ibm.com> References: <20140814001301.GI11121@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140814001301.GI11121@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Joonsoo Kim , David Rientjes , Han Pingtian , Pekka Enberg , Paul Mackerras , Benjamin Herrenschmidt , Michael Ellerman , Anton Blanchard , Matt Mackall , Christoph Lameter , Wanpeng Li , Tejun Heo , Linux Memory Management List , linuxppc-dev@lists.ozlabs.org On 13.08.2014 [17:13:01 -0700], Nishanth Aravamudan wrote: > Anton noticed (http://www.spinics.net/lists/linux-mm/msg67489.html) that > on ppc LPARs with memoryless nodes, a large amount of memory was > consumed by slabs and was marked unreclaimable. He tracked it down to > slab deactivations in the SLUB core when we allocate remotely, leading > to poor efficiency always when memoryless nodes are present. > > After much discussion, Joonsoo provided a few patches that help > significantly. They don't resolve the problem altogether: > > - memory hotplug still needs testing, that is when a memoryless node > becomes memory-ful, we want to dtrt > - there are other reasons for going off-node than memoryless nodes, > e.g., fully exhausted local nodes > > Neither case is resolved with this series, but I don't think that should > block their acceptance, as they can be explored/resolved with follow-on > patches. > > The series consists of: > > [1/4] topology: add support for node_to_mem_node() to determine the fallback node > [2/4] slub: fallback to node_to_mem_node() node if allocating on memoryless node > > - Joonsoo's patches to cache the nearest node with memory for each > NUMA node > > [3/4] Partial revert of 81c98869faa5 (""kthread: ensure locality of task_struct allocations") > > - At Tejun's request, keep the knowledge of memoryless node fallback to > the allocator core. > > [4/4] powerpc: reorder per-cpu NUMA information's initialization > > - Fix what appears to be a bug with when the NUMA topology information > is stored in the powerpc initialization code. Andrew & others, I know kernel summit is going on, so I'll be patient, but was just curious if anyone had any further comments other than Christoph's on the naming. Thanks, Nish > > arch/powerpc/kernel/smp.c | 12 ++++++------ > arch/powerpc/mm/numa.c | 13 ++++++++++--- > include/linux/topology.h | 17 +++++++++++++++++ > kernel/kthread.c | 2 +- > mm/page_alloc.c | 1 + > mm/slub.c | 24 ++++++++++++++++++------ > 6 files changed, 53 insertions(+), 16 deletions(-) -- 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