Re: [RFC 5/5] mm, page_alloc: disable pcplists during page isolation

From: Pavel Tatashin
Date: Wed Sep 09 2020 - 09:00:07 EST

> because we do not want to call out pcp free lists). I strongly suspect
> that only the memory hotplug really cares for this hard guanrantee.
> alloc_contig_range simply goes with EBUSY.

You are right, the strong requirement is for hotplug case only, but if
PCP disable/enable functionality is properly implemented, and we are
still draining the lists in alloc_contig_range case, I do not see a
reason not to disable/enable PCP during CMA as well just to reduce
number of spurious errors.