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* [PATCH 0/2] mm, memory_hotplug: fix uninitialized pages fallouts.
@ 2019-01-28 14:45 Michal Hocko
  2019-01-28 14:45 ` Michal Hocko
                   ` (4 more replies)
  0 siblings, 5 replies; 21+ messages in thread
From: Michal Hocko @ 2019-01-28 14:45 UTC (permalink / raw)
  To: Mikhail Zaslonko, Mikhail Gavrilov
  Cc: Andrew Morton, Pavel Tatashin, schwidefsky, heiko.carstens,
	gerald.schaefer, linux-mm, LKML

Hi,
Mikhail has posted fixes for the two bugs quite some time ago [1]. I
have pushed back on those fixes because I believed that it is much
better to plug the problem at the initialization time rather than play
whack-a-mole all over the hotplug code and find all the places which
expect the full memory section to be initialized. We have ended up with
2830bf6f05fb ("mm, memory_hotplug: initialize struct pages for the full
memory section") merged and cause a regression [2][3]. The reason is
that there might be memory layouts when two NUMA nodes share the same
memory section so the merged fix is simply incorrect.

In order to plug this hole we really have to be zone range aware in
those handlers. I have split up the original patch into two. One is
unchanged (patch 2) and I took a different approach for `removable'
crash. It would be great if Mikhail could test it still works for his
memory layout.

[1] http://lkml.kernel.org/r/20181105150401.97287-2-zaslonko@linux.ibm.com
[2] https://bugzilla.redhat.com/show_bug.cgi?id=1666948
[3] http://lkml.kernel.org/r/20190125163938.GA20411@dhcp22.suse.cz

^ permalink raw reply	[flat|nested] 21+ messages in thread

end of thread, other threads:[~2019-01-30  7:54 UTC | newest]

Thread overview: 21+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-01-28 14:45 [PATCH 0/2] mm, memory_hotplug: fix uninitialized pages fallouts Michal Hocko
2019-01-28 14:45 ` Michal Hocko
2019-01-28 14:45 ` [PATCH 1/2] mm, memory_hotplug: is_mem_section_removable do not pass the end of a zone Michal Hocko
2019-01-28 14:45   ` Michal Hocko
2019-01-29  9:06   ` Oscar Salvador
2019-01-29  9:12     ` Michal Hocko
2019-01-30  7:54       ` Oscar Salvador
2019-01-28 14:45 ` [PATCH 2/2] mm, memory_hotplug: test_pages_in_a_zone do not pass the end of zone Michal Hocko
2019-01-28 14:45   ` Michal Hocko
2019-01-29  9:09   ` Oscar Salvador
2019-01-29  9:13     ` Michal Hocko
2019-01-28 17:50 ` [PATCH 0/2] mm, memory_hotplug: fix uninitialized pages fallouts Andrew Morton
2019-01-28 17:50   ` Andrew Morton
2019-01-28 18:41   ` Michal Hocko
2019-01-28 18:45     ` Michal Hocko
2019-01-29 13:14 ` Gerald Schaefer
2019-01-29 13:49   ` Michal Hocko
2019-01-29 14:08     ` Gerald Schaefer
2019-01-29 17:38     ` Mikhail Gavrilov
2019-01-29 20:24       ` Michal Hocko
2019-01-29 20:56         ` Mikhail Gavrilov

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