Re: [PATCH v2 1/1] mm: only dispaly online cpus of the numa node

[Leizhen (ThunderTown)]

On 2017/10/3 21:56, Michal Hocko wrote:
> On Tue 03-10-17 14:47:26, Will Deacon wrote:
>> On Mon, Oct 02, 2017 at 02:54:46PM -0700, Andrew Morton wrote:
>>> On Mon, 2 Oct 2017 11:38:07 +0100 Will Deacon <will.deacon@xxxxxxx> wrote:
>>>
>>>>> When I executed numactl -H(which read /sys/devices/system/node/nodeX/cpumap
>>>>> and display cpumask_of_node for each node), but I got different result on
>>>>> X86 and arm64. For each numa node, the former only displayed online CPUs,
>>>>> and the latter displayed all possible CPUs. Unfortunately, both Linux
>>>>> documentation and numactl manual have not described it clear.
>>>>>
>>>>> I sent a mail to ask for help, and Michal Hocko <mhocko@xxxxxxxxxx> replied
>>>>> that he preferred to print online cpus because it doesn't really make much
>>>>> sense to bind anything on offline nodes.
>>>>>
>>>>> Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
>>>>> Acked-by: Michal Hocko <mhocko@xxxxxxxx>
>>>>> ---
>>>>>  drivers/base/node.c | 12 ++++++++++--
>>>>>  1 file changed, 10 insertions(+), 2 deletions(-)
>>>>
>>>> Which tree is this intended to go through? I'm happy to take it via arm64,
>>>> but I don't want to tread on anybody's toes in linux-next and it looks like
>>>> there are already queued changes to this file via Andrew's tree.
>>>
>>> I grabbed it.  I suppose there's some small risk of userspace breakage
>>> so I suggest it be a 4.15-rc1 thing?
>>
>> To be honest, I suspect the vast majority (if not all) code that reads this
>> file was developed for x86, so having the same behaviour for arm64 sounds
>> like something we should do ASAP before people try to special case with
>> things like #ifdef __aarch64__.
>>
>> I'd rather have this in 4.14 if possible.
> 
> Agreed!
> 

+1

-- 
Thanks!
BestRegards