[PATCH v18 00/26] Add generic memory shrinker to VirtIO-GPU and Panfrost DRM drivers
Dmitry Osipenko
dmitry.osipenko at collabora.com
Sun Oct 29 23:01:39 UTC 2023
This series:
1. Adds common drm-shmem memory shrinker
2. Enables shrinker for VirtIO-GPU driver
3. Switches Panfrost driver to the common shrinker
4. Fixes bugs and improves drm-shmem code
Mesa: https://gitlab.freedesktop.org/digetx/mesa/-/commits/virgl-madvise
IGT: https://gitlab.freedesktop.org/digetx/igt-gpu-tools/-/commits/virtio-madvise
https://gitlab.freedesktop.org/digetx/igt-gpu-tools/-/commits/panfrost-madvise
Changelog:
v18:- Added new pathes that change sgt allocation policy. Previously once
sgt was allocated, it exsited till GEM was freed. Now sgt is destroyed
once pages are unpinned and drivers have to manage the pages' pinning
refcounting by themselves using get/put() and pin/unpin() pages.
This removes pages refcounting ambiguity from the drm-shmem core.
- Dropped patch that changed drm_gem_shmem_vmap_locked() error handling,
like was requested by Boris Brezillon.
- Added new patches that make minor improvements:
- Optimize unlocked get_pages_sgt()
- Don't free refcounted GEM
- Dropped t-b from the Panfrost shrinker patch that was given for older
patch version since code changed with the new sgt allocation policy.
v17:- Dropped patches that added new drm-shmem sgt flags, fixing dma-buf UAF
in drm-prime error code path and preventing invalid page_count when GEM
is freed. Will revist them later on and then factor them out into a
seprate patchset.
- Dropped patches that replaced drm_gem_shmem_free() with
drm_gem_object_put(), they not needed anymore after changing
drm_gem_shmem_free() to not touch reservation lock.
- Addressed review comments from Boris Brezillon:
- Added new patch to clean up error unwinding in
drm_gem_shmem_vmap_locked()
- Added new __drm_gem_shmem_put_pages() to let the callers
to assert the held reservation lock themselves
- Moved replacement of shmem->pages check with refcount_read()
in drm_gem_shmem_free() to the shrinker addition patch
- Improved commit message of the vmap_use_count patch
- Added r-bs from Boris Brezillon that he gave to v16
v16:- Added more comments to the code for the new drm-shmem flags
- Added r-bs from Boris Brezillon
- Fixed typos and made impovements pointed out by Boris Brezillon
- Replaced kref with refcount_t as was suggested by Boris Brezillon
- Corrected placement of got_sgt flag in the Lima driver, also renamed
flag to got_pages_sgt
- Removed drm_gem_shmem_resv_assert_held() and made drm_gem_shmem_free()
to free pages without a new func that doesn't touch resv lock, as was
suggested by Boris Brezillon
- Added pages_pin_count to drm_gem_shmem_print_info()
v15:- Moved drm-shmem reference counters to use kref that allows to
optimize unlocked functions, like was suggested by Boris Brezillon.
- Changed drm/gem/shmem function names to use _locked postfix and
dropped the _unlocked, making the naming scheme consistent across
DRM code, like was suggested by Boris Brezillon.
- Added patch that fixes UAF in drm-shmem for drivers that import
dma-buf and then release buffer in the import error code path.
- Added patch that makes drm-shmem use new flag for SGT's get_pages()
refcounting, preventing unbalanced refcounting when GEM is freed.
- Fixed guest blob pinning in virtio-gpu driver that was missed
previously in the shrinker patch.
- Moved VC4 and virtio-gpu drivers to use drm_gem_put() in
GEM-creation error code paths, which is now required by drm-shmem
and was missed in a previous patch versions.
- Virtio-GPU now attaches shmem pages to host on first use and not
when BO is created. In older patch versions there was a potential
race condition in the BO creation code path where both
get_sgt()+object_attach() should've been made under same resv lock,
otherwise pages could be evicted before attachment is invoked.
- Virtio-GPU and drm-shmem shrinker patches are split into smaller
ones.
v14:- All the prerequisite reservation locking patches landed upstream,
previously were a part of this series in v13 and older.
https://lore.kernel.org/dri-devel/20230529223935.2672495-1-dmitry.osipenko@collabora.com/
- Added patches to improve locked/unlocked function names, like was
suggested by Boris Brezillon for v13.
- Made all exported drm-shmem symbols GPL, like was previously
discussed with Thomas Zimmermann on this series.
- Improved virtio-gpu shrinker patch. Now it won't detach purged BO
when userspace closes GEM. Crosvm (and not qemu) checks res_id on
CMD_CTX_DETACH_RESOURCE and prints noisy error message if ID is
invalid, which wasn't noticed before.
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@collabora.com/T/
Dmitry Osipenko (26):
drm/gem: Change locked/unlocked postfix of drm_gem_v/unmap() function
names
drm/gem: Add _locked postfix to functions that have unlocked
counterpart
drm/shmem-helper: Make all exported symbols GPL
drm/shmem-helper: Refactor locked/unlocked functions
drm/shmem-helper: Remove obsoleted is_iomem test
drm/shmem-helper: Add and use pages_pin_count
drm/shmem-helper: Use refcount_t for pages_use_count
drm/shmem-helper: Add and use lockless drm_gem_shmem_get_pages()
drm/shmem-helper: Switch drm_gem_shmem_vmap/vunmap to use pin/unpin
drm/shmem-helper: Use refcount_t for vmap_use_count
drm/shmem-helper: Prepare drm_gem_shmem_free() to shrinker addition
drm/shmem-helper: Make drm_gem_shmem_get_pages() public
drm/shmem-helper: Add drm_gem_shmem_put_pages()
drm/lima: Explicitly get and put drm-shmem pages
drm/panfrost: Explicitly get and put drm-shmem pages
drm/virtio: Explicitly get and put drm-shmem pages
drm/v3d: Explicitly get and put drm-shmem pages
drm/shmem-helper: Change sgt allocation policy
drm/shmem-helper: Add common memory shrinker
drm/shmem-helper: Export drm_gem_shmem_get_pages_sgt_locked()
drm/shmem-helper: Optimize unlocked get_pages_sgt()
drm/shmem-helper: Don't free refcounted GEM
drm/virtio: Pin display framebuffer BO
drm/virtio: Attach shmem BOs dynamically
drm/virtio: Support shmem shrinking
drm/panfrost: Switch to generic memory shrinker
drivers/gpu/drm/drm_client.c | 6 +-
drivers/gpu/drm/drm_gem.c | 26 +-
drivers/gpu/drm/drm_gem_framebuffer_helper.c | 6 +-
drivers/gpu/drm/drm_gem_shmem_helper.c | 644 +++++++++++++++---
drivers/gpu/drm/drm_internal.h | 4 +-
drivers/gpu/drm/drm_prime.c | 4 +-
drivers/gpu/drm/lima/lima_gem.c | 28 +-
drivers/gpu/drm/lima/lima_gem.h | 1 +
drivers/gpu/drm/lima/lima_sched.c | 4 +-
drivers/gpu/drm/panfrost/Makefile | 1 -
drivers/gpu/drm/panfrost/panfrost_device.h | 4 -
drivers/gpu/drm/panfrost/panfrost_drv.c | 29 +-
drivers/gpu/drm/panfrost/panfrost_dump.c | 4 +-
drivers/gpu/drm/panfrost/panfrost_gem.c | 57 +-
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 | 26 +-
drivers/gpu/drm/panfrost/panfrost_perfcnt.c | 6 +-
drivers/gpu/drm/v3d/v3d_bo.c | 15 +-
drivers/gpu/drm/virtio/virtgpu_drv.h | 22 +-
drivers/gpu/drm/virtio/virtgpu_gem.c | 80 +++
drivers/gpu/drm/virtio/virtgpu_ioctl.c | 57 +-
drivers/gpu/drm/virtio/virtgpu_kms.c | 8 +
drivers/gpu/drm/virtio/virtgpu_object.c | 147 +++-
drivers/gpu/drm/virtio/virtgpu_plane.c | 17 +-
drivers/gpu/drm/virtio/virtgpu_submit.c | 15 +-
drivers/gpu/drm/virtio/virtgpu_vq.c | 40 ++
include/drm/drm_device.h | 10 +-
include/drm/drm_gem.h | 6 +-
include/drm/drm_gem_shmem_helper.h | 125 +++-
include/uapi/drm/virtgpu_drm.h | 14 +
32 files changed, 1159 insertions(+), 396 deletions(-)
delete mode 100644 drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
--
2.41.0
More information about the dri-devel
mailing list