From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752348AbaANG42 (ORCPT ); Tue, 14 Jan 2014 01:56:28 -0500 Received: from relay.parallels.com ([195.214.232.42]:53169 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751709AbaANG41 (ORCPT ); Tue, 14 Jan 2014 01:56:27 -0500 Message-ID: <52D4DF97.1010409@parallels.com> Date: Tue, 14 Jan 2014 10:56:23 +0400 From: Vladimir Davydov MIME-Version: 1.0 To: Andrew Morton CC: , , , Mel Gorman , Michal Hocko , Johannes Weiner , Rik van Riel , Dave Chinner , Glauber Costa Subject: Re: [PATCH 3/5] mm: vmscan: respect NUMA policy mask when shrinking slab on direct reclaim References: <7d37542211678a637dc6b4d995fd6f1e89100538.1389443272.git.vdavydov@parallels.com> <20140113151132.d07cbc938baf5af70f929120@linux-foundation.org> In-Reply-To: <20140113151132.d07cbc938baf5af70f929120@linux-foundation.org> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.30.16.96] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/14/2014 03:11 AM, Andrew Morton wrote: > On Sat, 11 Jan 2014 16:36:33 +0400 Vladimir Davydov wrote: > >> When direct reclaim is executed by a process bound to a set of NUMA >> nodes, we should scan only those nodes when possible, but currently we >> will scan kmem from all online nodes even if the kmem shrinker is NUMA >> aware. That said, binding a process to a particular NUMA node won't >> prevent it from shrinking inode/dentry caches from other nodes, which is >> not good. Fix this. > Seems right. I worry that reducing the amount of shrinking which > node-bound processes perform might affect workloads in unexpected ways. Theoretically, it might, especially for NUMA unaware shrinkers. But that's how it works for cpusets right now - we do not count pages from nodes that are not allowed for the current process. Besides, when counting lru pages for kswapd_shrink_zones(), we also consider only the node this kswapd runs on so that NUMA unaware shrinkers will be scanned more aggressively on NUMA enabled setups than NUMA aware ones. So, in fact, this patch makes policy masks handling consistent with the rest of the vmscan code. > I think I'll save this one for 3.15-rc1, OK? OK, thanks.