Re: [PATCH v2 0/5] mm: support parallel free of memory

[Aaron Lu]

On Wed, Mar 15, 2017 at 05:28:43PM +0100, Michal Hocko wrote:
... ...
> After all the amount of the work to be done is the same we just risk
> more lock contentions, unexpected CPU usage etc.

I start to realize this is a good question.

I guess max_active=4 produced almost the best result(max_active=8 is
only slightly better) is due to the test box is a 4 node machine and
therefore, there are 4 zone->lock to contend(let's ignore those tiny
zones only available in node 0).

I'm going to test on a EP to see if max_active=2 will suffice to produce
a good enough result. If so, the proper default number should be the
number of nodes.

Thanks.