From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qc0-f182.google.com (mail-qc0-f182.google.com [209.85.216.182]) by kanga.kvack.org (Postfix) with ESMTP id 3C1A56B009B for ; Tue, 9 Sep 2014 15:02:12 -0400 (EDT) Received: by mail-qc0-f182.google.com with SMTP id x13so4923945qcv.27 for ; Tue, 09 Sep 2014 12:02:11 -0700 (PDT) Received: from e9.ny.us.ibm.com (e9.ny.us.ibm.com. [32.97.182.139]) by mx.google.com with ESMTPS id f39si6712652qge.69.2014.09.09.12.02.10 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 09 Sep 2014 12:02:11 -0700 (PDT) Received: from /spool/local by e9.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 9 Sep 2014 15:02:09 -0400 Received: from b01cxnp22033.gho.pok.ibm.com (b01cxnp22033.gho.pok.ibm.com [9.57.198.23]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 8B1E538C8067 for ; Tue, 9 Sep 2014 15:02:05 -0400 (EDT) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by b01cxnp22033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id s89J25tt38011058 for ; Tue, 9 Sep 2014 19:02:05 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 s89J23IH019919 for ; Tue, 9 Sep 2014 15:02:05 -0400 Date: Tue, 9 Sep 2014 12:01:54 -0700 From: Nishanth Aravamudan Subject: [PATCH 0/3] Improve slab consumption with memoryless nodes Message-ID: <20140909190154.GC22906@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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 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: [1/3] topology: add support for node_to_mem_node() to determine the fallback node [2/3] 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 [3/3] 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. include/linux/topology.h | 17 +++++++++++++++++ kernel/kthread.c | 2 +- mm/page_alloc.c | 1 + mm/slub.c | 24 ++++++++++++++++++------ 4 files changed, 37 insertions(+), 7 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