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SubjectRe: [PATCH 0/3] mmu notifier contextual informations
Date
Am 03.12.18 um 21:18 schrieb jglisse@redhat.com:
> From: Jérôme Glisse <jglisse@redhat.com>
>
> This patchset add contextual information, why an invalidation is
> happening, to mmu notifier callback. This is necessary for user
> of mmu notifier that wish to maintains their own data structure
> without having to add new fields to struct vm_area_struct (vma).
>
> For instance device can have they own page table that mirror the
> process address space. When a vma is unmap (munmap() syscall) the
> device driver can free the device page table for the range.
>
> Today we do not have any information on why a mmu notifier call
> back is happening and thus device driver have to assume that it
> is always an munmap(). This is inefficient at it means that it
> needs to re-allocate device page table on next page fault and
> rebuild the whole device driver data structure for the range.
>
> Other use case beside munmap() also exist, for instance it is
> pointless for device driver to invalidate the device page table
> when the invalidation is for the soft dirtyness tracking. Or
> device driver can optimize away mprotect() that change the page
> table permission access for the range.
>
> This patchset enable all this optimizations for device driver.
> I do not include any of those in this serie but other patchset
> i am posting will leverage this.
>
>
> From code point of view the patchset is pretty simple, the first
> two patches consolidate all mmu notifier arguments into a struct
> so that it is easier to add/change arguments. The last patch adds
> the contextual information (munmap, protection, soft dirty, clear,
> ...).

Skimming over it at least the parts I'm familiar with look completely
sane to me.

Whole series is Acked-by: Christian König <christian.koenig@amd.com>.

Regards,
Christian.

>
> Cheers,
> Jérôme
>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Matthew Wilcox <mawilcox@microsoft.com>
> Cc: Ross Zwisler <zwisler@kernel.org>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Radim Krčmář <rkrcmar@redhat.com>
> Cc: Michal Hocko <mhocko@kernel.org>
> Cc: Christian Koenig <christian.koenig@amd.com>
> Cc: Felix Kuehling <felix.kuehling@amd.com>
> Cc: Ralph Campbell <rcampbell@nvidia.com>
> Cc: John Hubbard <jhubbard@nvidia.com>
> Cc: kvm@vger.kernel.org
> Cc: linux-rdma@vger.kernel.org
> Cc: linux-fsdevel@vger.kernel.org
> Cc: dri-devel@lists.freedesktop.org
>
> Jérôme Glisse (3):
> mm/mmu_notifier: use structure for invalidate_range_start/end callback
> mm/mmu_notifier: use structure for invalidate_range_start/end calls
> mm/mmu_notifier: contextual information for event triggering
> invalidation
>
> drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 43 ++++-----
> drivers/gpu/drm/i915/i915_gem_userptr.c | 14 ++-
> drivers/gpu/drm/radeon/radeon_mn.c | 16 ++--
> drivers/infiniband/core/umem_odp.c | 20 ++---
> drivers/infiniband/hw/hfi1/mmu_rb.c | 13 ++-
> drivers/misc/mic/scif/scif_dma.c | 11 +--
> drivers/misc/sgi-gru/grutlbpurge.c | 14 ++-
> drivers/xen/gntdev.c | 12 +--
> fs/dax.c | 11 ++-
> fs/proc/task_mmu.c | 10 ++-
> include/linux/mm.h | 4 +-
> include/linux/mmu_notifier.h | 106 +++++++++++++++-------
> kernel/events/uprobes.c | 13 +--
> mm/hmm.c | 23 ++---
> mm/huge_memory.c | 58 ++++++------
> mm/hugetlb.c | 63 +++++++------
> mm/khugepaged.c | 13 +--
> mm/ksm.c | 26 +++---
> mm/madvise.c | 22 ++---
> mm/memory.c | 112 ++++++++++++++----------
> mm/migrate.c | 30 ++++---
> mm/mmu_notifier.c | 22 +++--
> mm/mprotect.c | 17 ++--
> mm/mremap.c | 14 +--
> mm/oom_kill.c | 20 +++--
> mm/rmap.c | 34 ++++---
> virt/kvm/kvm_main.c | 14 ++-
> 27 files changed, 421 insertions(+), 334 deletions(-)
>

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