Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756530AbZKKDXl (ORCPT ); Tue, 10 Nov 2009 22:23:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756170AbZKKDXl (ORCPT ); Tue, 10 Nov 2009 22:23:41 -0500 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:52847 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755568AbZKKDXk (ORCPT ); Tue, 10 Nov 2009 22:23:40 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: David Rientjes Subject: Re: [BUGFIX][PATCH] oom-kill: fix NUMA consraint check with nodemask v3 Cc: kosaki.motohiro@jp.fujitsu.com, KAMEZAWA Hiroyuki , Daisuke Nishimura , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Christoph Lameter In-Reply-To: References: <20091111115217.FD56.A69D9226@jp.fujitsu.com> Message-Id: <20091111121958.FD59.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Wed, 11 Nov 2009 12:23:43 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2227 Lines: 56 > On Wed, 11 Nov 2009, KOSAKI Motohiro wrote: > > > > > { > > > > -#ifdef CONFIG_NUMA > > > > struct zone *zone; > > > > struct zoneref *z; > > > > enum zone_type high_zoneidx = gfp_zone(gfp_mask); > > > > - nodemask_t nodes = node_states[N_HIGH_MEMORY]; > > > > + int ret = CONSTRAINT_NONE; > > > > > > > > - for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) > > > > - if (cpuset_zone_allowed_softwall(zone, gfp_mask)) > > > > - node_clear(zone_to_nid(zone), nodes); > > > > - else > > > > + /* > > > > + * The nodemask here is a nodemask passed to alloc_pages(). Now, > > > > + * cpuset doesn't use this nodemask for its hardwall/softwall/hierarchy > > > > + * feature. mempolicy is an only user of nodemask here. > > > > + */ > > > > + if (nodemask) { > > > > + nodemask_t mask; > > > > + /* check mempolicy's nodemask contains all N_HIGH_MEMORY */ > > > > + nodes_and(mask, *nodemask, node_states[N_HIGH_MEMORY]); > > > > + if (!nodes_equal(mask, node_states[N_HIGH_MEMORY])) > > > > + return CONSTRAINT_MEMORY_POLICY; > > > > + } > > > > > > Although a nodemask_t was previously allocated on the stack, we should > > > probably change this to use NODEMASK_ALLOC() for kernels with higher > > > CONFIG_NODES_SHIFT since allocations can happen very deep into the stack. > > > > No. NODEMASK_ALLOC() is crap. we should remove it. > > I've booted 1K node systems and have found it to be helpful to ensure that > the stack will not overflow especially in areas where we normally are deep > already, such as in the page allocator. Linux doesn't support 1K nodes. (and only SGI huge machine use 512 nodes) At least, NODEMASK_ALLOC should make more cleaner interface. current one and struct nodemask_scratch are pretty ugly. > > btw, CPUMASK_ALLOC was already removed. > > I don't remember CPUMASK_ALLOC() actually being merged. I know the > comment exists in nodemask.h, but I don't recall any CPUMASK_ALLOC() users > in the tree. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/