]> git.baikalelectronics.ru Git - kernel.git/commit
mm: disable NUMA_BALANCING_DEFAULT_ENABLED and TRANSPARENT_HUGEPAGE on PREEMPT_RT
authorSebastian Andrzej Siewior <bigeasy@linutronix.de>
Fri, 5 Nov 2021 20:35:27 +0000 (13:35 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 6 Nov 2021 20:30:33 +0000 (13:30 -0700)
commit97247d0a7df2a1fdeb651f74d7edc6449221ed22
tree2d64713fbc901708c7937970a768174446a4cb74
parent3058153ff30b03c7fda932f0ca74ebb97e0d39b8
mm: disable NUMA_BALANCING_DEFAULT_ENABLED and TRANSPARENT_HUGEPAGE on PREEMPT_RT

TRANSPARENT_HUGEPAGE:
  There are potential non-deterministic delays to an RT thread if a
  critical memory region is not THP-aligned and a non-RT buffer is
  located in the same hugepage-aligned region. It's also possible for an
  unrelated thread to migrate pages belonging to an RT task incurring
  unexpected page faults due to memory defragmentation even if
  khugepaged is disabled.

Regular HUGEPAGEs are not affected by this can be used.

NUMA_BALANCING:
  There is a non-deterministic delay to mark PTEs PROT_NONE to gather
  NUMA fault samples, increased page faults of regions even if mlocked
  and non-deterministic delays when migrating pages.

[Mel Gorman worded 99% of the commit description].

Link: https://lore.kernel.org/all/20200304091159.GN3818@techsingularity.net/
Link: https://lore.kernel.org/all/20211026165100.ahz5bkx44lrrw5pt@linutronix.de/
Link: https://lkml.kernel.org/r/20211028143327.hfbxjze7palrpfgp@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
init/Kconfig
mm/Kconfig