Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933848Ab0BEVHN (ORCPT ); Fri, 5 Feb 2010 16:07:13 -0500 Received: from smtp-out.google.com ([216.239.44.51]:57861 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933834Ab0BEVHG (ORCPT ); Fri, 5 Feb 2010 16:07:06 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id: references:user-agent:mime-version:content-type:x-system-of-record; b=huO1RqMDR7TGXepcd1w6s3nSNDfkWPxwtFEB1wWnRnFsMVgGfIaF+ex6bwEwfB41C nlwQLnvIbjbMPBc0jfTdA== Date: Fri, 5 Feb 2010 13:06:56 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Andi Kleen cc: submit@firstfloor.org, linux-kernel@vger.kernel.org, haicheng.li@intel.com, Pekka Enberg , linux-mm@kvack.org Subject: Re: [PATCH] [1/4] SLAB: Handle node-not-up case in fallback_alloc() In-Reply-To: <20100203213912.D3081B1620@basil.firstfloor.org> Message-ID: References: <201002031039.710275915@firstfloor.org> <20100203213912.D3081B1620@basil.firstfloor.org> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2220 Lines: 70 On Wed, 3 Feb 2010, Andi Kleen wrote: > When fallback_alloc() runs the node of the CPU might not be initialized yet. > Handle this case by allocating in another node. > That other node must be allowed by current's cpuset, otherwise kmem_getpages() will fail when get_page_from_freelist() iterates only over unallowed nodes. > Signed-off-by: Andi Kleen > > --- > mm/slab.c | 19 ++++++++++++++++++- > 1 file changed, 18 insertions(+), 1 deletion(-) > > Index: linux-2.6.33-rc3-ak/mm/slab.c > =================================================================== > --- linux-2.6.33-rc3-ak.orig/mm/slab.c > +++ linux-2.6.33-rc3-ak/mm/slab.c > @@ -3210,7 +3210,24 @@ retry: > if (local_flags & __GFP_WAIT) > local_irq_enable(); > kmem_flagcheck(cache, flags); > - obj = kmem_getpages(cache, local_flags, numa_node_id()); > + > + /* > + * Node not set up yet? Try one that the cache has been set up > + * for. > + */ > + nid = numa_node_id(); > + if (cache->nodelists[nid] == NULL) { > + for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { > + nid = zone_to_nid(zone); > + if (cache->nodelists[nid]) > + break; If you set a bit in a nodemask_t everytime ____cache_alloc_node() fails in the previous for_each_zone_zonelist() iteration, you could just iterate that nodemask here without duplicating the zone_to_nid() and cache->nodelists[nid] != NULL check. nid = numa_node_id(); if (!cache->nodelists[nid]) for_each_node_mask(nid, allowed_nodes) { obj = kmem_getpages(cache, local_flags, nid); if (obj) break; } else obj = kmem_getpages(cache, local_flags, nid); This way you can try all allowed nodes for memory instead of just one when cache->nodelists[numa_node_id()] == NULL. > + } > + if (!cache->nodelists[nid]) > + return NULL; > + } > + > + > + obj = kmem_getpages(cache, local_flags, nid); > if (local_flags & __GFP_WAIT) > local_irq_disable(); > if (obj) { -- 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/