[PATCH 0/2] mm/compaction: some fix for the range passed to pageblock_pfn_to_page()

[Wei Yang <richard.weiyang@gmail.com>]

During the code reading of isolate_migratepages_range(), first spot the range
passed to pageblock_pfn_to_page() is different from that to
isolate_migratepages_block().

This implies there is a chance that pageblock_pfn_to_page() thinks the range
is in the same zone, but isolate_migratepages_block() will isolate range in
two different zones. This is not what we expect.

Then I found pageblock_pfn_to_page() has an optimization if zone->contiguous,
this means even the range is across two different zones, it will think the
range is within the same zone.

So introduce two patches to fix it:

Patch 1: check the range belongs to the zone first
Patch 2: pass the correct range to pageblock_pfn_to_page()

Wei Yang (2):
  mm/compaction: check the range to pageblock_pfn_to_page() is within
    the zone first
  mm/compaction: fix the range to pageblock_pfn_to_page()

 mm/compaction.c | 37 ++++++++++++++-----------------------
 mm/internal.h   |  3 +++
 2 files changed, 17 insertions(+), 23 deletions(-)

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2.34.1