[PATCH v13 00/10] Add generic memory shrinker to VirtIO-GPU and Panfrost DRM drivers

From: Dmitry Osipenko
Date: Mon Mar 13 2023 - 22:28:14 EST


This series:

1. Adds common drm-shmem memory shrinker
2. Enables shrinker for VirtIO-GPU driver
3. Switches Panfrost driver to the common shrinker

Changelog:

v13:- Updated virtio-gpu shrinker patch to use drm_gem_shmem_object_pin()
directly instead of drm_gem_pin() and dropped patch that exported
drm_gem_pin() functions, like was requested by Thomas Zimmermann in
v12.

v12:- Fixed the "no previous prototype for function" warning reported by
kernel build bot for v11.

- Fixed the missing reservation lock reported by Intel CI for VGEM
driver. Other drivers using drm-shmem were affected similarly to
VGEM. The problem was in the dma-buf attachment code path that led
to drm-shmem pinning function which assumed the held reservation lock
by drm_gem_pin(). In the past that code path was causing trouble for
i915 driver and we've changed the locking scheme for the attachment
code path in the dma-buf core to let exporters to handle the locking
themselves. After a closer investigation, I realized that my assumption
about testing of dma-buf export code path using Panfrost driver was
incorrect. Now I created additional local test to exrecise the Panfrost
export path. I also reproduced the issue reported by the Intel CI for
v10. It's all fixed now by making the drm_gem_shmem_pin() to take the
resv lock by itself.

- Patches are based on top of drm-tip, CC'd intel-gfx CI for testing.

v11:- Rebased on a recent linux-next. Added new patch as a result:

drm/shmem-helper: Export drm_gem_shmem_get_pages_sgt_locked()

It's needed by the virtio-gpu driver to swap-in/unevict shmem
object, previously get_pages_sgt() didn't use locking.

- Separated the "Add memory shrinker" patch into smaller parts to ease
the reviewing, as was requested by Thomas Zimmermann:

drm/shmem-helper: Factor out pages alloc/release from
drm_gem_shmem_get/put_pages()
drm/shmem-helper: Add pages_pin_count field
drm/shmem-helper: Switch drm_gem_shmem_vmap/vunmap to use pin/unpin
drm/shmem-helper: Factor out unpinning part from drm_gem_shmem_purge()

- Addessed the v10 review comments from Thomas Zimmermann: return errno
instead of bool, sort code alphabetically, rename function and etc
minor changes.

- Added new patch to remove the "map->is_iomem" from drm-shmem, as
was suggested by Thomas Zimmermann.

- Added acks and r-b's that were given to v10.

v10:- Was partially applied to misc-fixes/next.

https://lore.kernel.org/dri-devel/6c16f303-81df-7ebe-85e9-51bb40a8b301@xxxxxxxxxxxxx/T/

Dmitry Osipenko (10):
drm/shmem-helper: Switch to reservation lock
drm/shmem-helper: Factor out pages alloc/release from
drm_gem_shmem_get/put_pages()
drm/shmem-helper: Add pages_pin_count field
drm/shmem-helper: Switch drm_gem_shmem_vmap/vunmap to use pin/unpin
drm/shmem-helper: Factor out unpinning part from drm_gem_shmem_purge()
drm/shmem-helper: Add memory shrinker
drm/shmem-helper: Remove obsoleted is_iomem test
drm/shmem-helper: Export drm_gem_shmem_get_pages_sgt_locked()
drm/virtio: Support memory shrinking
drm/panfrost: Switch to generic memory shrinker

drivers/gpu/drm/drm_gem_shmem_helper.c | 613 ++++++++++++++----
drivers/gpu/drm/lima/lima_gem.c | 8 +-
drivers/gpu/drm/panfrost/Makefile | 1 -
drivers/gpu/drm/panfrost/panfrost_device.h | 4 -
drivers/gpu/drm/panfrost/panfrost_drv.c | 34 +-
drivers/gpu/drm/panfrost/panfrost_gem.c | 30 +-
drivers/gpu/drm/panfrost/panfrost_gem.h | 9 -
.../gpu/drm/panfrost/panfrost_gem_shrinker.c | 122 ----
drivers/gpu/drm/panfrost/panfrost_job.c | 18 +-
drivers/gpu/drm/panfrost/panfrost_mmu.c | 19 +-
drivers/gpu/drm/virtio/virtgpu_drv.h | 20 +-
drivers/gpu/drm/virtio/virtgpu_gem.c | 68 ++
drivers/gpu/drm/virtio/virtgpu_ioctl.c | 37 ++
drivers/gpu/drm/virtio/virtgpu_kms.c | 8 +
drivers/gpu/drm/virtio/virtgpu_object.c | 137 +++-
drivers/gpu/drm/virtio/virtgpu_plane.c | 17 +-
drivers/gpu/drm/virtio/virtgpu_vq.c | 40 ++
include/drm/drm_device.h | 10 +-
include/drm/drm_gem_shmem_helper.h | 83 ++-
include/uapi/drm/virtgpu_drm.h | 14 +
20 files changed, 925 insertions(+), 367 deletions(-)
delete mode 100644 drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c

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2.39.2