From: Vlastimil Babka Subject: Re: [PATCH] ovs: do not allocate memory from offline numa node Date: Mon, 5 Oct 2015 15:59:20 +0200 Message-ID: <56128238.8010305@suse.cz> References: <20151002101822.12499.27658.stgit@buzz> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org To: Konstantin Khlebnikov , dev@openvswitch.org, Pravin Shelar , "David S. Miller" Return-path: In-Reply-To: <20151002101822.12499.27658.stgit@buzz> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 10/02/2015 12:18 PM, Konstantin Khlebnikov wrote: > When openvswitch tries allocate memory from offline numa node 0: > stats = kmem_cache_alloc_node(flow_stats_cache, GFP_KERNEL | __GFP_ZERO, 0) > It catches VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES || !node_online(nid)) > [ replaced with VM_WARN_ON(!node_online(nid)) recently ] in linux/gfp.h > This patch disables numa affinity in this case. > > Signed-off-by: Konstantin Khlebnikov ... > diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c > index f2ea83ba4763..c7f74aab34b9 100644 > --- a/net/openvswitch/flow_table.c > +++ b/net/openvswitch/flow_table.c > @@ -93,7 +93,8 @@ struct sw_flow *ovs_flow_alloc(void) > > /* Initialize the default stat node. */ > stats = kmem_cache_alloc_node(flow_stats_cache, > - GFP_KERNEL | __GFP_ZERO, 0); > + GFP_KERNEL | __GFP_ZERO, > + node_online(0) ? 0 : NUMA_NO_NODE); Stupid question: can node 0 become offline between this check, and the VM_WARN_ON? :) BTW what kind of system has node 0 offline? > if (!stats) > goto err; > >