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
..
arm	arm64 updates for 4.16:	2018-01-30 13:57:43 -08:00
async_pf.c	kvm,async_pf: Use swq_has_sleeper()	2017-09-15 16:57:11 +02:00
async_pf.h	KVM: fix checkpatch.pl errors in kvm/async_pf.h	2015-06-19 17:16:25 +02:00
coalesced_mmio.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
coalesced_mmio.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
eventfd.c	annotate poll-related wait keys	2017-11-27 16:19:54 -05:00
irqchip.c	KVM: use rcu access function for irq routing	2017-07-07 15:24:15 +02:00
Kconfig	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
kvm_main.c	mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks	2018-01-31 17:18:38 -08:00
vfio.c	vfio: New external user group/file match	2017-06-28 13:50:05 -06:00
vfio.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00