Re: [PATCH v2 4/5] mm: use node_page_state_snapshot to avoid deviation

From: kemi
Date: Wed Dec 20 2017 - 20:41:09 EST




On 2017å12æ20æ 23:58, Christopher Lameter wrote:
> On Wed, 20 Dec 2017, kemi wrote:
>
>>> You are making numastats special and I yet haven't heard any sounds
>>> arguments for that. But that should be discussed in the respective
>>> patch.
>>>
>>
>> That is because we have much larger threshold size for NUMA counters, that means larger
>> deviation. So, the number in local cpus may not be simply ignored.
>
> Some numbers showing the effect of these changes would be helpful. You can
> probably create some in kernel synthetic tests to start with which would
> allow you to see any significant effects of those changes.
>
> Then run the larger testsuites (f.e. those that Mel has published) and
> benchmarks to figure out how behavior of real apps *may* change?
>

OK.
I will do that when available.
Let's just drop this patch in this series and consider this issue
in another patch.