OpenCloudOS-Kernel/drivers/misc/sgi-gru
David Rientjes 5ff7091f5a mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks
Commit 4d4bbd8526 ("mm, oom_reaper: skip mm structs with mmu
notifiers") prevented the oom reaper from unmapping private anonymous
memory with the oom reaper when the oom victim mm had mmu notifiers
registered.

The rationale is that doing mmu_notifier_invalidate_range_{start,end}()
around the unmap_page_range(), which is needed, can block and the oom
killer will stall forever waiting for the victim to exit, which may not
be possible without reaping.

That concern is real, but only true for mmu notifiers that have
blockable invalidate_range_{start,end}() callbacks.  This patch adds a
"flags" field to mmu notifier ops that can set a bit to indicate that
these callbacks do not block.

The implementation is steered toward an expensive slowpath, such as
after the oom reaper has grabbed mm->mmap_sem of a still alive oom
victim.

[rientjes@google.com: mmu_notifier_invalidate_range_end() can also call the invalidate_range() must not block, fix comment]
  Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1801091339570.240101@chino.kir.corp.google.com
[akpm@linux-foundation.org: make mm_has_blockable_invalidate_notifiers() return bool, use rwsem_is_locked()]
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1712141329500.74052@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Dimitri Sivanich <sivanich@hpe.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31 17:18:38 -08:00
..
Makefile misc: change to new flag variable 2011-03-17 14:05:34 +01:00
gru.h
gru_instructions.h Add #includes needed to permit the removal of asm/system.h 2012-03-28 18:30:03 +01:00
grufault.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
grufile.c x86/UV: Fix conditional in gru_exit() 2014-04-01 12:10:45 +02:00
gruhandles.c misc: sgi-gru: gruhandles.c: Remove unused function 2015-10-04 12:55:59 +01:00
gruhandles.h misc: sgi-gru: gruhandles.c: Remove unused function 2015-10-04 12:55:59 +01:00
grukdump.c drivers/misc/sgi-gru: remove always false condition 2015-09-20 19:27:59 -07:00
grukservices.c x86/platform/UV: Remove Obsolete GRU MMR address translation 2016-05-04 08:48:51 +02:00
grukservices.h
grulib.h
grumain.c mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmf 2017-02-24 17:46:54 -08:00
gruprocfs.c misc: replace strict_strtoul() with kstrtoul() 2013-06-06 12:54:08 -07:00
grutables.h mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmf 2017-02-24 17:46:54 -08:00
grutlbpurge.c mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks 2018-01-31 17:18:38 -08:00