[v2,0/2] mm: fix initialization of struct page for holes in memory layout

Message

Mike Rapoport Dec. 9, 2020, 9:43 p.m. UTC

From: Mike Rapoport <[e-mail]>

Hi,

Commit 73a6e474cb37 ("mm: memmap_init: iterate over
memblock regions rather that check each PFN") exposed several issues with
the memory map initialization and these patches fix those issues.

Initially there were crashes during compaction that Qian Cai reported back
in April [1]. It seemed back then that the probelm was fixed, but a few
weeks ago Andrea Arcangeli hit the same bug [2] and after a long discussion
between us [3] I think these patches are the proper fix.

v2 changes:
* added patch that adds all regions in memblock.reserved that do not
overlap with memblock.memory to memblock.memory in the beginning of
free_area_init()

[1] https://lore.kernel.org/lkml/[e-mail]
[2] https://lore.kernel.org/lkml/[e-mail]
[3] https://lore.kernel.org/mm-commits/[e-mail]

Mike Rapoport (2):
  mm: memblock: enforce overlap of memory.memblock and memory.reserved
  mm: fix initialization of struct page for holes in memory layout

 include/linux/memblock.h |   1 +
 mm/memblock.c            |  24 ++++++
 mm/page_alloc.c          | 159 ++++++++++++++++++---------------------
 3 files changed, 97 insertions(+), 87 deletions(-)