Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759880AbcJ1KTI (ORCPT ); Fri, 28 Oct 2016 06:19:08 -0400 Received: from foss.arm.com ([217.140.101.70]:55652 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754887AbcJ1KTG (ORCPT ); Fri, 28 Oct 2016 06:19:06 -0400 Date: Fri, 28 Oct 2016 11:19:05 +0100 From: Will Deacon To: David Daney Cc: linux-kernel@vger.kernel.org, Rob Herring , Frank Rowand , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Catalin Marinas , Robert Richter , Hanjun Guo , Ganapatrao Kulkarni , Gilbert Netzer , David Daney Subject: Re: [PATCH 1/2] of, numa: Add function to disable of_node_to_nid(). Message-ID: <20161028101905.GA6343@arm.com> References: <1477431061-7258-1-git-send-email-ddaney.cavm@gmail.com> <1477431061-7258-2-git-send-email-ddaney.cavm@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1477431061-7258-2-git-send-email-ddaney.cavm@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2415 Lines: 73 On Tue, Oct 25, 2016 at 02:31:00PM -0700, David Daney wrote: > From: David Daney > > On arm64 NUMA kernels we can pass "numa=off" on the command line to > disable NUMA. A side effect of this is that kmalloc_node() calls to > non-zero nodes will crash the system with an OOPS: > > [ 0.000000] [] __alloc_pages_nodemask+0xa4/0xe68 > [ 0.000000] [] new_slab+0xd0/0x57c > [ 0.000000] [] ___slab_alloc+0x2e4/0x514 > [ 0.000000] [] __slab_alloc+0x48/0x58 > [ 0.000000] [] __kmalloc_node+0xd0/0x2e0 > [ 0.000000] [] __irq_domain_add+0x7c/0x164 > [ 0.000000] [] its_probe+0x784/0x81c > [ 0.000000] [] its_init+0x48/0x1b0 > . > . > . > > This is caused by code like this in kernel/irq/irqdomain.c > > domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size), > GFP_KERNEL, of_node_to_nid(of_node)); > > When NUMA is disabled, the concept of a node is really undefined, so > of_node_to_nid() should unconditionally return NUMA_NO_NODE. > > Add __of_force_no_numa() to allow of_node_to_nid() to be forced to > return NUMA_NO_NODE. > > The follow on patch will call this new function from the arm64 numa > code. > > Reported-by: Gilbert Netzer > Signed-off-by: David Daney > --- > drivers/of/of_numa.c | 15 +++++++++++++++ > include/linux/of.h | 2 ++ > 2 files changed, 17 insertions(+) > > diff --git a/drivers/of/of_numa.c b/drivers/of/of_numa.c > index f63d4b0d..2212299 100644 > --- a/drivers/of/of_numa.c > +++ b/drivers/of/of_numa.c > @@ -150,12 +150,27 @@ static int __init of_numa_parse_distance_map(void) > return ret; > } > > +static bool of_force_no_numa; > + > +void __of_force_no_numa(void) > +{ > + of_force_no_numa = true; > +} > + > int of_node_to_nid(struct device_node *device) > { > struct device_node *np; > u32 nid; > int r = -ENODATA; > > + /* > + * If NUMA forced off, nodes are meaningless. Return > + * NUMA_NO_NODE so that any node specific memory allocations > + * can succeed from the default pool. > + */ > + if (of_force_no_numa) > + return NUMA_NO_NODE; Why don't you just check if the nid you get back from the device is set in numa_nodes_parsed and return NUMA_NO_NODE if not? Will