On 2017/11/29 20:03, Michal Hocko wrote:
> On Wed 29-11-17 17:13:27, zhong jiang wrote:
>> Currently, Arm64 and x86 use the common code wehn parsing numa node
>> in a acpi way. The arm64 will set the parsed node in numa_add_memblk,
>> but the x86 is not set in that , then it will result in the repeatly
>> setting. And the parsed node maybe is unreasonable to the system.
>>
>> we would better not set it although it also still works. because the
>> parsed node is unresonable. so we should skip related operate in this
>> node. This patch just set node in various architecture individually.
>> it is no functional change.
> I really have hard time to understand what you try to say above. Could
> you start by the problem description and then how you are addressing it?
I am so sorry for that. I will make the issue clear.
Arm64 get numa information through acpi. The code flow is as follows.
arm64_acpi_numa_init
acpi_parse_memory_affinity
acpi_numa_memory_affinity_init
numa_add_memblk(nid, start, end); //it will set node to numa_nodes_parsed successfully.
node_set(node, numa_nodes_parsed); // numa_add_memblk had set that. it will repeat.
the root cause is that X86 parse numa also go through above code. and arch-related
numa_add_memblk is not set the parsed node to numa_nodes_parsed. it need
additional node_set(node, numa_parsed) to handle. therefore, the issue will be introduced.
menawhile, the parsed node is meaningless when numa_add_memblk fails and return 0.
so we should bail out in time.
is it a little clearer ?
Thanks
zhongjiang
>> Signed-off-by: zhong jiang <zhongjiang@xxxxxxxxxx>
>> ---
>> arch/x86/mm/amdtopology.c | 1 -
>> arch/x86/mm/numa.c | 3 ++-
>> drivers/acpi/numa.c | 5 ++++-
>> 3 files changed, 6 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/x86/mm/amdtopology.c b/arch/x86/mm/amdtopology.c
>> index 91f501b..7657042 100644
>> --- a/arch/x86/mm/amdtopology.c
>> +++ b/arch/x86/mm/amdtopology.c
>> @@ -151,7 +151,6 @@ int __init amd_numa_init(void)
>>
>> prevbase = base;
>> numa_add_memblk(nodeid, base, limit);
>> - node_set(nodeid, numa_nodes_parsed);
>> }
>>
>> if (!nodes_weight(numa_nodes_parsed))
>> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
>> index 25504d5..8f87f26 100644
>> --- a/arch/x86/mm/numa.c
>> +++ b/arch/x86/mm/numa.c
>> @@ -150,6 +150,8 @@ static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
>> mi->blk[mi->nr_blks].end = end;
>> mi->blk[mi->nr_blks].nid = nid;
>> mi->nr_blks++;
>> +
>> + node_set(nid, numa_nodes_parsed);
>> return 0;
>> }
>>
>> @@ -693,7 +695,6 @@ static int __init dummy_numa_init(void)
>> printk(KERN_INFO "Faking a node at [mem %#018Lx-%#018Lx]\n",
>> 0LLU, PFN_PHYS(max_pfn) - 1);
>>
>> - node_set(0, numa_nodes_parsed);
>> numa_add_memblk(0, 0, PFN_PHYS(max_pfn));
>>
>> return 0;
>> diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c
>> index 917f1cc..f2e33cb 100644
>> --- a/drivers/acpi/numa.c
>> +++ b/drivers/acpi/numa.c
>> @@ -294,7 +294,9 @@ void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
>> goto out_err_bad_srat;
>> }
>>
>> - node_set(node, numa_nodes_parsed);
>> + /* some architecture is likely to ignore a unreasonable node */
>> + if (!node_isset(node, numa_nodes_parsed))
>> + goto out;
>>
>> pr_info("SRAT: Node %u PXM %u [mem %#010Lx-%#010Lx]%s%s\n",
>> node, pxm,
>> @@ -309,6 +311,7 @@ void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
>>
>> max_possible_pfn = max(max_possible_pfn, PFN_UP(end - 1));
>>
>> +out:
>> return 0;
>> out_err_bad_srat:
>> bad_srat();
>> --
>> 1.8.3.1
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