[PATCH v6 0/8] mmu notifier provide context informations
Jerome Glisse
jglisse at redhat.com
Tue Apr 9 14:21:26 UTC 2019
Andrew anything blocking this for 5.2 ? Should i ask people (ie the end
user of this) to re-ack v6 (it is the same as previous version just rebase
and dropped kvm bits).
On Tue, Mar 26, 2019 at 12:47:39PM -0400, jglisse at redhat.com wrote:
> From: Jérôme Glisse <jglisse at redhat.com>
>
> (Andrew this apply on top of my HMM patchset as otherwise you will have
> conflict with changes to mm/hmm.c)
>
> Changes since v5:
> - drop KVM bits waiting for KVM people to express interest if they
> do not then i will post patchset to remove change_pte_notify as
> without the changes in v5 change_pte_notify is just useless (it
> it is useless today upstream it is just wasting cpu cycles)
> - rebase on top of lastest Linus tree
>
> Previous cover letter with minor update:
>
>
> Here i am not posting users of this, they already have been posted to
> appropriate mailing list [6] and will be merge through the appropriate
> tree once this patchset is upstream.
>
> Note that this serie does not change any behavior for any existing
> code. It just pass down more information to mmu notifier listener.
>
> The rational for this patchset:
>
> CPU page table update can happens for many reasons, not only as a
> result of a syscall (munmap(), mprotect(), mremap(), madvise(), ...)
> but also as a result of kernel activities (memory compression, reclaim,
> migration, ...).
>
> This patch introduce a set of enums that can be associated with each
> of the events triggering a mmu notifier:
>
> - UNMAP: munmap() or mremap()
> - CLEAR: page table is cleared (migration, compaction, reclaim, ...)
> - PROTECTION_VMA: change in access protections for the range
> - PROTECTION_PAGE: change in access protections for page in the range
> - SOFT_DIRTY: soft dirtyness tracking
>
> Being able to identify munmap() and mremap() from other reasons why the
> page table is cleared is important to allow user of mmu notifier to
> update their own internal tracking structure accordingly (on munmap or
> mremap it is not longer needed to track range of virtual address as it
> becomes invalid). Without this serie, driver are force to assume that
> every notification is an munmap which triggers useless trashing within
> drivers that associate structure with range of virtual address. Each
> driver is force to free up its tracking structure and then restore it
> on next device page fault. With this serie we can also optimize device
> page table update [6].
>
> More over this can also be use to optimize out some page table updates
> like for KVM where we can update the secondary MMU directly from the
> callback instead of clearing it.
>
> ACKS AMD/RADEON https://lkml.org/lkml/2019/2/1/395
> ACKS RDMA https://lkml.org/lkml/2018/12/6/1473
>
> Cheers,
> Jérôme
>
> [1] v1 https://lkml.org/lkml/2018/3/23/1049
> [2] v2 https://lkml.org/lkml/2018/12/5/10
> [3] v3 https://lkml.org/lkml/2018/12/13/620
> [4] v4 https://lkml.org/lkml/2019/1/23/838
> [5] v5 https://lkml.org/lkml/2019/2/19/752
> [6] patches to use this:
> https://lkml.org/lkml/2019/1/23/833
> https://lkml.org/lkml/2019/1/23/834
> https://lkml.org/lkml/2019/1/23/832
> https://lkml.org/lkml/2019/1/23/831
>
> Cc: Andrew Morton <akpm at linux-foundation.org>
> Cc: linux-mm at kvack.org
> Cc: Christian König <christian.koenig at amd.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Cc: Jan Kara <jack at suse.cz>
> Cc: Andrea Arcangeli <aarcange at redhat.com>
> Cc: Peter Xu <peterx at redhat.com>
> Cc: Felix Kuehling <Felix.Kuehling at amd.com>
> Cc: Jason Gunthorpe <jgg at mellanox.com>
> Cc: Ross Zwisler <zwisler at kernel.org>
> Cc: Dan Williams <dan.j.williams at intel.com>
> Cc: Paolo Bonzini <pbonzini at redhat.com>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Cc: Radim Krčmář <rkrcmar at redhat.com>
> Cc: Michal Hocko <mhocko at kernel.org>
> Cc: Christian Koenig <christian.koenig at amd.com>
> Cc: Ben Skeggs <bskeggs at redhat.com>
> Cc: Ralph Campbell <rcampbell at nvidia.com>
> Cc: John Hubbard <jhubbard at nvidia.com>
> Cc: kvm at vger.kernel.org
> Cc: dri-devel at lists.freedesktop.org
> Cc: linux-rdma at vger.kernel.org
> Cc: Arnd Bergmann <arnd at arndb.de>
>
> Jérôme Glisse (8):
> mm/mmu_notifier: helper to test if a range invalidation is blockable
> mm/mmu_notifier: convert user range->blockable to helper function
> mm/mmu_notifier: convert mmu_notifier_range->blockable to a flags
> mm/mmu_notifier: contextual information for event enums
> mm/mmu_notifier: contextual information for event triggering
> invalidation v2
> mm/mmu_notifier: use correct mmu_notifier events for each invalidation
> mm/mmu_notifier: pass down vma and reasons why mmu notifier is
> happening v2
> mm/mmu_notifier: mmu_notifier_range_update_to_read_only() helper
>
> drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 8 ++--
> drivers/gpu/drm/i915/i915_gem_userptr.c | 2 +-
> drivers/gpu/drm/radeon/radeon_mn.c | 4 +-
> drivers/infiniband/core/umem_odp.c | 5 +-
> drivers/xen/gntdev.c | 6 +--
> fs/proc/task_mmu.c | 3 +-
> include/linux/mmu_notifier.h | 63 +++++++++++++++++++++++--
> kernel/events/uprobes.c | 3 +-
> mm/hmm.c | 6 +--
> mm/huge_memory.c | 14 +++---
> mm/hugetlb.c | 12 +++--
> mm/khugepaged.c | 3 +-
> mm/ksm.c | 6 ++-
> mm/madvise.c | 3 +-
> mm/memory.c | 25 ++++++----
> mm/migrate.c | 5 +-
> mm/mmu_notifier.c | 12 ++++-
> mm/mprotect.c | 4 +-
> mm/mremap.c | 3 +-
> mm/oom_kill.c | 3 +-
> mm/rmap.c | 6 ++-
> virt/kvm/kvm_main.c | 3 +-
> 22 files changed, 147 insertions(+), 52 deletions(-)
>
> --
> 2.20.1
>
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