FROMLIST: BACKPORT: mm/page_alloc: Remotely drain per-cpu lists

Some setups, notably NOHZ_FULL CPUs, are too busy to handle the per-cpu
drain work queued by __drain_all_pages(). So introduce new a mechanism
to remotely drain the per-cpu lists. It is made possible by remotely
locking 'struct per_cpu_pages' new per-cpu spinlocks. A benefit of this
new scheme is that drain operations are now migration safe.

There was no observed performance degradation vs. the previous scheme.
Both netperf and hackbench were run in parallel to triggering the
__drain_all_pages(NULL, true) code path around ~100 times per second.
The new scheme performs a bit better (~5%), although the important point
here is there are no performance regressions vs. the previous mechanism.
Per-cpu lists draining happens only in slow paths.

Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lore.kernel.org/all/20220420095906.27349-7-mgorman@techsingularity.net/



Conflicts:
	mm/page_alloc.c

1. aosp doesn't need 9c25cbfc, skip it

Bug: 230899966
Signed-off-by: Minchan Kim <minchan@google.com>
Change-Id: I8c4120d215836b04c53d0e4950a821fce4c99075