Andrew what is your plan for this ? I had a discussion with Peter Xu and Andrea about change_pte() and kvm. Today the change_pte() kvm optimization is effectively disabled because of invalidate_range calls. With a minimal couple lines patch on top of this patchset we can bring back the kvm change_pte optimization and we can also optimize some other cases like for instance when write protecting after fork (but i am not sure this is something qemu does often so it might not help for real kvm workload). I will be posting a the extra patch as an RFC, but in the meantime i wanted to know what was the status for this. Jan, Christian does your previous ACK still holds for this ? On Wed, Jan 23, 2019 at 05:23:06PM -0500, jglisse@xxxxxxxxxx wrote: > From: Jérôme Glisse <jglisse@xxxxxxxxxx> > > Hi Andrew, i see that you still have my event patch in you queue [1]. > This patchset replace that single patch and is broken down in further > step so that it is easier to review and ascertain that no mistake were > made during mechanical changes. Here are the step: > > Patch 1 - add the enum values > Patch 2 - coccinelle semantic patch to convert all call site of > mmu_notifier_range_init to default enum value and also > to passing down the vma when it is available > Patch 3 - update many call site to more accurate enum values > Patch 4 - add the information to the mmu_notifier_range struct > Patch 5 - helper to test if a range is updated to read only > > All the remaining patches are update to various driver to demonstrate > how this new information get use by device driver. I build tested > with make all and make all minus everything that enable mmu notifier > ie building with MMU_NOTIFIER=no. Also tested with some radeon,amd > gpu and intel gpu. > > If they are no objections i believe best plan would be to merge the > the first 5 patches (all mm changes) through your queue for 5.1 and > then to delay driver update to each individual driver tree for 5.2. > This will allow each individual device driver maintainer time to more > thouroughly test this more then my own testing. > > Note that i also intend to use this feature further in nouveau and > HMM down the road. I also expect that other user like KVM might be > interested into leveraging this new information to optimize some of > there secondary page table invalidation. > > Here is an explaination on 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. Latter patches take advantages of > those enum values. > > - 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). > > [1] https://www.ozlabs.org/~akpm/mmotm/broken-out/mm-mmu_notifier-contextual-information-for-event-triggering-invalidation-v2.patch > > Cc: Christian König <christian.koenig@xxxxxxx> > Cc: Jan Kara <jack@xxxxxxx> > Cc: Felix Kuehling <Felix.Kuehling@xxxxxxx> > Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> > Cc: Ross Zwisler <zwisler@xxxxxxxxxx> > Cc: Dan Williams <dan.j.williams@xxxxxxxxx> > Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> > Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxxxxx> > Cc: Ralph Campbell <rcampbell@xxxxxxxxxx> > Cc: John Hubbard <jhubbard@xxxxxxxxxx> > Cc: kvm@xxxxxxxxxxxxxxx > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx > Cc: linux-rdma@xxxxxxxxxxxxxxx > Cc: linux-fsdevel@xxxxxxxxxxxxxxx > Cc: Arnd Bergmann <arnd@xxxxxxxx> > > Jérôme Glisse (9): > mm/mmu_notifier: contextual information for event enums > mm/mmu_notifier: contextual information for event triggering > invalidation > mm/mmu_notifier: use correct mmu_notifier events for each invalidation > mm/mmu_notifier: pass down vma and reasons why mmu notifier is > happening > mm/mmu_notifier: mmu_notifier_range_update_to_read_only() helper > gpu/drm/radeon: optimize out the case when a range is updated to read > only > gpu/drm/amdgpu: optimize out the case when a range is updated to read > only > gpu/drm/i915: optimize out the case when a range is updated to read > only > RDMA/umem_odp: optimize out the case when a range is updated to read > only > > drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 13 ++++++++ > drivers/gpu/drm/i915/i915_gem_userptr.c | 16 ++++++++++ > drivers/gpu/drm/radeon/radeon_mn.c | 13 ++++++++ > drivers/infiniband/core/umem_odp.c | 22 +++++++++++-- > fs/proc/task_mmu.c | 3 +- > include/linux/mmu_notifier.h | 42 ++++++++++++++++++++++++- > include/rdma/ib_umem_odp.h | 1 + > kernel/events/uprobes.c | 3 +- > mm/huge_memory.c | 14 +++++---- > mm/hugetlb.c | 11 ++++--- > mm/khugepaged.c | 3 +- > mm/ksm.c | 6 ++-- > mm/madvise.c | 3 +- > mm/memory.c | 25 +++++++++------ > mm/migrate.c | 5 ++- > mm/mmu_notifier.c | 10 ++++++ > mm/mprotect.c | 4 ++- > mm/mremap.c | 3 +- > mm/oom_kill.c | 3 +- > mm/rmap.c | 6 ++-- > 20 files changed, 171 insertions(+), 35 deletions(-) > > -- > 2.17.2 > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
