Am 30.06.21 um 03:34 schrieb John Stultz:
After an unfortunately long pause (covid work-schedule burnout), I wanted to revive and resubmit this series.
As before, the point of this series is trying to add both a page pool as well as deferred-freeingto the DMA-BUF system heap to improve allocation performance (so that it can match or beat the old ION system heaps performance).
The combination of the page pool along with deferred freeing allows us to offload page-zeroing out of the allocation hot path. This was done originally with ION and this patch series allows the DMA-BUF system heap to match ION's system heap allocation performance in a simple microbenchmark [1] (ION re-added to the kernel for comparision, running on an x86 vm image):
./dmabuf-heap-bench -i 0 1 system Testing dmabuf system vs ion heaptype 0 (flags: 0x1)
dmabuf heap: alloc 4096 bytes 5000 times in 79314244 ns 15862 ns/call ion heap: alloc 4096 bytes 5000 times in 107390769 ns 21478 ns/call dmabuf heap: alloc 1048576 bytes 5000 times in 259083419 ns 51816 ns/call ion heap: alloc 1048576 bytes 5000 times in 340497344 ns 68099 ns/call dmabuf heap: alloc 8388608 bytes 5000 times in 2603105563 ns 520621 ns/call ion heap: alloc 8388608 bytes 5000 times in 3613592860 ns 722718 ns/call dmabuf heap: alloc 33554432 bytes 5000 times in 12212492979 ns 2442498 ns/call ion heap: alloc 33554432 bytes 5000 times in 14584157792 ns 2916831 ns/call
Daniel didn't like earlier attempts to re-use the network page-pool code to achieve this, and suggested the ttm_pool be used instead, so this series pulls the page pool functionality out of the ttm_pool logic and creates a generic page pool that can be shared.
New in v9:
- Tried to address Christian König's feedback on the page pool changes (Kerneldoc, static functions, locking issues, duplicative order tracking)
- Fix up Kconfig dependency issue as Reported-by: kernel test robot lkp@intel.com
- Fix compiler warning Reported-by: kernel test robot lkp@intel.com
I know Christian had some less specific feedback on the deferred free work that I'd like to revisit, but I wanted to restart the discussion with this new series, rather then trying to dregdge up and reply to a ~4mo old thread.
I was already wondering where this was left :)
The kernel test robot pointed out quite a number of bugs. I suggest to fix those first and then take a look at my comments on patch #1.
Regards, Christian.
Input would be greatly appreciated. Testing as well, as I don't have any development hardware that utilizes the ttm pool.
Thanks -john
[1] https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fandroid.go...
Cc: Daniel Vetter daniel@ffwll.ch Cc: Christian Koenig christian.koenig@amd.com Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Liam Mark lmark@codeaurora.org Cc: Chris Goldsworthy cgoldswo@codeaurora.org Cc: Laura Abbott labbott@kernel.org Cc: Brian Starkey Brian.Starkey@arm.com Cc: Hridya Valsaraju hridya@google.com Cc: Suren Baghdasaryan surenb@google.com Cc: Sandeep Patil sspatil@google.com Cc: Daniel Mentz danielmentz@google.com Cc: Ørjan Eide orjan.eide@arm.com Cc: Robin Murphy robin.murphy@arm.com Cc: Ezequiel Garcia ezequiel@collabora.com Cc: Simon Ser contact@emersion.fr Cc: James Jones jajones@nvidia.com Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org
John Stultz (5): drm: Add a sharable drm page-pool implementation drm: ttm_pool: Rework ttm_pool to use drm_page_pool dma-buf: system_heap: Add drm pagepool support to system heap dma-buf: heaps: Add deferred-free-helper library code dma-buf: system_heap: Add deferred freeing to the system heap
drivers/dma-buf/heaps/Kconfig | 5 + drivers/dma-buf/heaps/Makefile | 1 + drivers/dma-buf/heaps/deferred-free-helper.c | 138 +++++++++ drivers/dma-buf/heaps/deferred-free-helper.h | 55 ++++ drivers/dma-buf/heaps/system_heap.c | 46 ++- drivers/gpu/drm/Kconfig | 4 + drivers/gpu/drm/Makefile | 2 + drivers/gpu/drm/page_pool.c | 297 +++++++++++++++++++ drivers/gpu/drm/ttm/ttm_pool.c | 167 ++--------- include/drm/page_pool.h | 68 +++++ include/drm/ttm/ttm_pool.h | 14 +- 11 files changed, 643 insertions(+), 154 deletions(-) create mode 100644 drivers/dma-buf/heaps/deferred-free-helper.c create mode 100644 drivers/dma-buf/heaps/deferred-free-helper.h create mode 100644 drivers/gpu/drm/page_pool.c create mode 100644 include/drm/page_pool.h