Web lists-archives.com

[PATCHv2 0/7] x86_64/mm: remove bottom-up allocation style by pushing forward the parsing of mem hotplug info




Background
When kaslr kernel can be guaranteed to sit inside unmovable node
after [1]. But if kaslr kernel is located near the end of the movable node,
then bottom-up allocator may create pagetable which crosses the boundary
between unmovable node and movable node.  It is a probability issue,
two factors include -1. how big the gap between kernel end and
unmovable node's end.  -2. how many memory does the system own.
Alternative way to fix this issue is by increasing the gap by
boot/compressed/kaslr*. But taking the scenario of PB level memory,
the pagetable will take server MB even if using 1GB page, different page
attr and fragment will make things worse. So it is hard to decide how much
should the gap increase.
The following figure show the defection of current bottom-up style:
  [startA, endA][startB, "kaslr kernel verly close to" endB][startC, endC]

If nodeA,B is unmovable, while nodeC is movable, then init_mem_mapping()
can generate pgtable on nodeC, which stain movable node.

This patch makes it certainty instead of a probablity problem. It achieves
this by pushing forward the parsing of mem hotplug info ahead of init_mem_mapping().

Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Chao Fan <fanc.fnst@xxxxxxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: linux-acpi@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Pingfan Liu (7):
  x86/mm: concentrate the code to memblock allocator enabled
  acpi: change the topo of acpi_table_upgrade()
  mm/memblock: introduce allocation boundary for tracing purpose
  x86/setup: parse acpi to get hotplug info before init_mem_mapping()
  x86/mm: set allowed range for memblock allocator
  x86/mm: remove bottom-up allocation style for x86_64
  x86/mm: isolate the bottom-up style to init_32.c

 arch/arm/mm/init.c              |   3 +-
 arch/arm/mm/mmu.c               |   4 +-
 arch/arm/mm/nommu.c             |   2 +-
 arch/arm64/kernel/setup.c       |   2 +-
 arch/csky/kernel/setup.c        |   2 +-
 arch/microblaze/mm/init.c       |   2 +-
 arch/mips/kernel/setup.c        |   2 +-
 arch/powerpc/mm/40x_mmu.c       |   6 +-
 arch/powerpc/mm/44x_mmu.c       |   2 +-
 arch/powerpc/mm/8xx_mmu.c       |   2 +-
 arch/powerpc/mm/fsl_booke_mmu.c |   5 +-
 arch/powerpc/mm/hash_utils_64.c |   4 +-
 arch/powerpc/mm/init_32.c       |   2 +-
 arch/powerpc/mm/pgtable-radix.c |   2 +-
 arch/powerpc/mm/ppc_mmu_32.c    |   8 +-
 arch/powerpc/mm/tlb_nohash.c    |   6 +-
 arch/unicore32/mm/mmu.c         |   2 +-
 arch/x86/kernel/setup.c         |  93 ++++++++++++++---------
 arch/x86/mm/init.c              | 163 +++++-----------------------------------
 arch/x86/mm/init_32.c           | 147 ++++++++++++++++++++++++++++++++++++
 arch/x86/mm/mm_internal.h       |   8 +-
 arch/xtensa/mm/init.c           |   2 +-
 drivers/acpi/tables.c           |   4 +-
 include/linux/acpi.h            |   5 +-
 include/linux/memblock.h        |  10 ++-
 mm/memblock.c                   |  23 ++++--
 26 files changed, 290 insertions(+), 221 deletions(-)

-- 
2.7.4