On Fri, Aug 19, 2016 at 7:28 AM, zhong jiang <zhongji...@huawei.com> wrote: > On 2016/8/19 1:45, Ganapatrao Kulkarni wrote: >> On Thu, Aug 18, 2016 at 9:34 PM, Catalin Marinas >> <catalin.mari...@arm.com> wrote: >>> On Thu, Aug 18, 2016 at 09:09:26PM +0800, zhongjiang wrote: >>>> At present, boot cpu will bound to a node from device tree when node_off >>>> enable. >>>> if the node is not initialization, it will lead to a following problem. >>>> >>>> next_zones_zonelist+0x18/0x80 >>>> __build_all_zonelists+0x1e0/0x288 >>>> build_all_zonelists_init+0x10/0x1c >>>> build_all_zonelists+0x114/0x128 >>>> start_kernel+0x1a0/0x414 >>> I think this "problem" is missing a lot of information. Is this supposed >>> to be a kernel panic? >>> >>>> The patch fix it by fallback to node 0. therefore, the cpu will bound to >>>> the node >>>> correctly. >>>> >>>> Signed-off-by: zhongjiang <zhongji...@huawei.com> >>>> --- >>>> arch/arm64/mm/numa.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c >>>> index 4dcd7d6..1f8f5da 100644 >>>> --- a/arch/arm64/mm/numa.c >>>> +++ b/arch/arm64/mm/numa.c >>>> @@ -119,7 +119,7 @@ void numa_store_cpu_info(unsigned int cpu) >>>> void __init early_map_cpu_to_node(unsigned int cpu, int nid) >>>> { >>>> /* fallback to node 0 */ >>>> - if (nid < 0 || nid >= MAX_NUMNODES) >>>> + if (nid < 0 || nid >= MAX_NUMNODES || numa_off) >> i did not understood how this line change fixes the issue that you >> have mentioned (i too not understood fully the issue description) >> this array used while mapping node id when secondary cores comes up >> when numa_off is set the cpu_to_node_map[cpu] is not used and set to >> node0 always( refer function numa_store_cpu_info).. >> please provide more details to understand the issue you are facing. >> /* >> * Set the cpu to node and mem mapping >> */ >> void numa_store_cpu_info(unsigned int cpu) >> { >> map_cpu_to_node(cpu, numa_off ? 0 : cpu_to_node_map[cpu]); >> } >> >> thanks >> Ganapat > The issue comes up when we test the kdump. it will leads to kernel crash. > when I debug the issue, I find boot cpu actually bound to the node1. while > node1 is not real existence when numa_off enable.
boot cpu is default mapped to node0 are you running with any other patches? > > __build_all_zonelists will call the cpu_to_node[cpu], but orresponding > relation > will be obtained from the devicetree. therefore, the issue will come up. when numa_off, all cpus are mapped to node0( refer numa_store_cpu_info) and device tree mapping is ignored. > The corresponding message is as follows when kdump start. it is obvious that > mem > range points to the node1 in the devicetree. > > Early memory node ranges > node 0: [mem 0x0000005fe0000000-0x0000005fffffffff] > Initmem setup node 0 [mem 0x0000005fe0000000-0x0000005fffffffff] > > Unable to handle kernel paging request at virtual address 00001690 > pgd = ffff800001226000 > [00001690] *pgd=0000000000000000 > Internal error: Oops: 96000004 [#1] SMP > Modules linked in: > CPU: 0 PID: 0 Comm: swapper Not tainted 4.1.27-vhulk3.6.5.aarch64 #1 > Hardware name: Hisilicon Hi1612 Development Board (DT) > task: ffff80000102b730 ti: ffff800001018000 task.ti: ffff800001018000 > PC is at next_zones_zonelist+0x18/0x80 > LR is at __build_all_zonelists+0x1e0/0x288 > next_zones_zonelist+0x18/0x80 > __build_all_zonelists+0x1e0/0x288 > build_all_zonelists_init+0x10/0x1c > build_all_zonelists+0x114/0x128 > start_kernel+0x1a0/0x414 >>>> nid = 0; >>>> >>>> cpu_to_node_map[cpu] = nid; >>> The patch looks fine (slight inconsistence from the map_cpu_to_node() >>> callers but I guess we don't want to expose numa_off outside this file). >>> I would however like to see an Ack from Ganapat (cc'ed). >>> >>> -- >>> Catalin >>> >>> _______________________________________________ >>> linux-arm-kernel mailing list >>> linux-arm-ker...@lists.infradead.org >>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >> . >> > >