| Message ID | 20190806231548.25242-1-jgg@ziepe.ca (mailing list archive) |
|---|---|
| Headers | show |
| Series | Add mmu_notifier_get/put for managing mmu notifier registrations | expand |
On 8/6/19 4:15 PM, Jason Gunthorpe wrote: > From: Jason Gunthorpe <jgg@mellanox.com> > > This series introduces a new registration flow for mmu_notifiers based on > the idea that the user would like to get a single refcounted piece of > memory for a mm, keyed to its use. > > For instance many users of mmu_notifiers use an interval tree or similar > to dispatch notifications to some object. There are many objects but only > one notifier subscription per mm holding the tree. > > Of the 12 places that call mmu_notifier_register: > - 7 are maintaining some kind of obvious mapping of mm_struct to > mmu_notifier registration, ie in some linked list or hash table. Of > the 7 this series converts 4 (gru, hmm, RDMA, radeon) > > - 3 (hfi1, gntdev, vhost) are registering multiple notifiers, but each > one immediately does some VA range filtering, ie with an interval tree. > These would be better with a global subsystem-wide range filter and > could convert to this API. > > - 2 (kvm, amd_iommu) are deliberately using a single mm at a time, and > really can't use this API. One of the intel-svm's modes is also in this > list > > The 3/7 unconverted drivers are: > - intel-svm > This driver tracks mm's in a global linked list 'global_svm_list' > and would benefit from this API. > > Its flow is a bit complex, since it also wants a set of non-shared > notifiers. > > - i915_gem_usrptr > This driver tracks mm's in a per-device hash > table (dev_priv->mm_structs), but only has an optional use of > mmu_notifiers. Since it still seems to need the hash table it is > difficult to convert. > > - amdkfd/kfd_process > This driver is using a global SRCU hash table to track mm's > > The control flow here is very complicated and the driver is relying on > this hash table to be fast on the ioctl syscall path. > > It would definitely benefit, but only if the ioctl path didn't need to > do the search so often. > > This series is already entangled with patches in the hmm & RDMA tree and > will require some git topic branches for the RDMA ODP stuff. I intend for > it to go through the hmm tree. > > There is a git version here: > > https://github.com/jgunthorpe/linux/commits/mmu_notifier > > Which has the required pre-patches for the RDMA ODP conversion that are > still being reviewed. > > Jason Gunthorpe (11): > mm/mmu_notifiers: hoist do_mmu_notifier_register down_write to the > caller > mm/mmu_notifiers: do not speculatively allocate a mmu_notifier_mm > mm/mmu_notifiers: add a get/put scheme for the registration > misc/sgi-gru: use mmu_notifier_get/put for struct gru_mm_struct > hmm: use mmu_notifier_get/put for 'struct hmm' > RDMA/odp: use mmu_notifier_get/put for 'struct ib_ucontext_per_mm' > RDMA/odp: remove ib_ucontext from ib_umem > drm/radeon: use mmu_notifier_get/put for struct radeon_mn > drm/amdkfd: fix a use after free race with mmu_notifer unregister > drm/amdkfd: use mmu_notifier_put > mm/mmu_notifiers: remove unregister_no_release > > drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 1 + > drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 3 - > drivers/gpu/drm/amd/amdkfd/kfd_process.c | 88 ++++----- > drivers/gpu/drm/nouveau/nouveau_drm.c | 3 + > drivers/gpu/drm/radeon/radeon.h | 3 - > drivers/gpu/drm/radeon/radeon_device.c | 2 - > drivers/gpu/drm/radeon/radeon_drv.c | 2 + > drivers/gpu/drm/radeon/radeon_mn.c | 157 ++++------------ > drivers/infiniband/core/umem.c | 4 +- > drivers/infiniband/core/umem_odp.c | 183 ++++++------------ > drivers/infiniband/core/uverbs_cmd.c | 3 - > drivers/infiniband/core/uverbs_main.c | 1 + > drivers/infiniband/hw/mlx5/main.c | 5 - > drivers/misc/sgi-gru/grufile.c | 1 + > drivers/misc/sgi-gru/grutables.h | 2 - > drivers/misc/sgi-gru/grutlbpurge.c | 84 +++------ > include/linux/hmm.h | 12 +- > include/linux/mm_types.h | 6 - > include/linux/mmu_notifier.h | 40 +++- > include/rdma/ib_umem.h | 2 +- > include/rdma/ib_umem_odp.h | 10 +- > include/rdma/ib_verbs.h | 3 - > kernel/fork.c | 1 - > mm/hmm.c | 121 +++--------- > mm/mmu_notifier.c | 230 +++++++++++++++++------ > 25 files changed, 408 insertions(+), 559 deletions(-) For the core MM, HMM, and nouveau changes you can add: Tested-by: Ralph Campbell <rcampbell@nvidia.com>
On Tue, Aug 06, 2019 at 08:15:37PM -0300, Jason Gunthorpe wrote: > This series is already entangled with patches in the hmm & RDMA tree and > will require some git topic branches for the RDMA ODP stuff. I intend for > it to go through the hmm tree. > Jason Gunthorpe (11): > mm/mmu_notifiers: hoist do_mmu_notifier_register down_write to the > caller > mm/mmu_notifiers: do not speculatively allocate a mmu_notifier_mm > mm/mmu_notifiers: add a get/put scheme for the registration > misc/sgi-gru: use mmu_notifier_get/put for struct gru_mm_struct > hmm: use mmu_notifier_get/put for 'struct hmm' > drm/radeon: use mmu_notifier_get/put for struct radeon_mn > drm/amdkfd: fix a use after free race with mmu_notifer unregister > drm/amdkfd: use mmu_notifier_put Other than these patches: > RDMA/odp: use mmu_notifier_get/put for 'struct ib_ucontext_per_mm' > RDMA/odp: remove ib_ucontext from ib_umem > mm/mmu_notifiers: remove unregister_no_release This series has been applied. I will apply the ODP patches when the series they depend on is merged to the RDMA tree Any further acks/remarks I will annotate, thanks in advance Thanks to all reviewers, Jason
On Tue, Aug 06, 2019 at 08:15:37PM -0300, Jason Gunthorpe wrote: > This series is already entangled with patches in the hmm & RDMA tree and > will require some git topic branches for the RDMA ODP stuff. I intend for > it to go through the hmm tree. The RDMA related patches have been applied to the RDMA tree on a shared topic branch, so I've merged that into hmm.git and applied the last patches from this series on top: > RDMA/odp: use mmu_notifier_get/put for 'struct ib_ucontext_per_mm' > RDMA/odp: remove ib_ucontext from ib_umem > mm/mmu_notifiers: remove unregister_no_release There was some conflict churn in the RDMA ODP patches vs what was used to the patches from this series, I fixed it up. Now I'm waiting for some testing feedback before pushing it to linux-next Thanks, Jason
From: Jason Gunthorpe <jgg@mellanox.com> This series introduces a new registration flow for mmu_notifiers based on the idea that the user would like to get a single refcounted piece of memory for a mm, keyed to its use. For instance many users of mmu_notifiers use an interval tree or similar to dispatch notifications to some object. There are many objects but only one notifier subscription per mm holding the tree. Of the 12 places that call mmu_notifier_register: - 7 are maintaining some kind of obvious mapping of mm_struct to mmu_notifier registration, ie in some linked list or hash table. Of the 7 this series converts 4 (gru, hmm, RDMA, radeon) - 3 (hfi1, gntdev, vhost) are registering multiple notifiers, but each one immediately does some VA range filtering, ie with an interval tree. These would be better with a global subsystem-wide range filter and could convert to this API. - 2 (kvm, amd_iommu) are deliberately using a single mm at a time, and really can't use this API. One of the intel-svm's modes is also in this list The 3/7 unconverted drivers are: - intel-svm This driver tracks mm's in a global linked list 'global_svm_list' and would benefit from this API. Its flow is a bit complex, since it also wants a set of non-shared notifiers. - i915_gem_usrptr This driver tracks mm's in a per-device hash table (dev_priv->mm_structs), but only has an optional use of mmu_notifiers. Since it still seems to need the hash table it is difficult to convert. - amdkfd/kfd_process This driver is using a global SRCU hash table to track mm's The control flow here is very complicated and the driver is relying on this hash table to be fast on the ioctl syscall path. It would definitely benefit, but only if the ioctl path didn't need to do the search so often. This series is already entangled with patches in the hmm & RDMA tree and will require some git topic branches for the RDMA ODP stuff. I intend for it to go through the hmm tree. There is a git version here: https://github.com/jgunthorpe/linux/commits/mmu_notifier Which has the required pre-patches for the RDMA ODP conversion that are still being reviewed. Jason Gunthorpe (11): mm/mmu_notifiers: hoist do_mmu_notifier_register down_write to the caller mm/mmu_notifiers: do not speculatively allocate a mmu_notifier_mm mm/mmu_notifiers: add a get/put scheme for the registration misc/sgi-gru: use mmu_notifier_get/put for struct gru_mm_struct hmm: use mmu_notifier_get/put for 'struct hmm' RDMA/odp: use mmu_notifier_get/put for 'struct ib_ucontext_per_mm' RDMA/odp: remove ib_ucontext from ib_umem drm/radeon: use mmu_notifier_get/put for struct radeon_mn drm/amdkfd: fix a use after free race with mmu_notifer unregister drm/amdkfd: use mmu_notifier_put mm/mmu_notifiers: remove unregister_no_release drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 1 + drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 3 - drivers/gpu/drm/amd/amdkfd/kfd_process.c | 88 ++++----- drivers/gpu/drm/nouveau/nouveau_drm.c | 3 + drivers/gpu/drm/radeon/radeon.h | 3 - drivers/gpu/drm/radeon/radeon_device.c | 2 - drivers/gpu/drm/radeon/radeon_drv.c | 2 + drivers/gpu/drm/radeon/radeon_mn.c | 157 ++++------------ drivers/infiniband/core/umem.c | 4 +- drivers/infiniband/core/umem_odp.c | 183 ++++++------------ drivers/infiniband/core/uverbs_cmd.c | 3 - drivers/infiniband/core/uverbs_main.c | 1 + drivers/infiniband/hw/mlx5/main.c | 5 - drivers/misc/sgi-gru/grufile.c | 1 + drivers/misc/sgi-gru/grutables.h | 2 - drivers/misc/sgi-gru/grutlbpurge.c | 84 +++------ include/linux/hmm.h | 12 +- include/linux/mm_types.h | 6 - include/linux/mmu_notifier.h | 40 +++- include/rdma/ib_umem.h | 2 +- include/rdma/ib_umem_odp.h | 10 +- include/rdma/ib_verbs.h | 3 - kernel/fork.c | 1 - mm/hmm.c | 121 +++--------- mm/mmu_notifier.c | 230 +++++++++++++++++------ 25 files changed, 408 insertions(+), 559 deletions(-)