The dma-map IOVA alloc, link, and sync APIs perform significantly better
than dma-map / dma-unmap, as they avoid costly IOMMU synchronizations.
This difference is especially noticeable when mapping a 2MB region in
4KB pages.
Use dma-map IOVA alloc, link, and sync APIs for GPU SVM and DRM page,
which mappings between the CPU and GPU.
Initial results are promising.
Baseline CPU time during 2M / 64K fault with a migration:
Average migrate 2M cpu time (us, percentage): 333.99665178571428571429,
.61102853199282922865
Average migrate 64K cpu time (us, percentage): 18.62723214285714285714,
.30127985269960467173
After this series CPU time during 2M / 64K fault with a migration:
Average migrate 2M cpu time (us, percentage): 224.81808035714285714286,
.51412827364772602557
Average migrate 64K cpu time (us, percentage): 14.65625000000000000000,
.25659463050529524405
Matt
v2:
- Include missing basline patch for CI
v3:
- Fix memory corruption
- PoC IOVA alloc for multi-GPU
v4:
- Pack IOVA / drop dummy pages
- Drop multi-GPU IOVA alloc
Francois Dugast (1):
drm/pagemap: Add helper to access zone_device_data
Matthew Brost (3):
drm/gpusvm: Use dma-map IOVA alloc, link, and sync API in GPU SVM
drm/pagemap: Split drm_pagemap_migrate_map_pages into device / system
drm/pagemap: Use dma-map IOVA alloc, link, and sync API for DRM
pagemap
drivers/gpu/drm/drm_gpusvm.c | 62 +++++++--
drivers/gpu/drm/drm_pagemap.c | 229 +++++++++++++++++++++++++---------
include/drm/drm_gpusvm.h | 5 +
include/drm/drm_pagemap.h | 14 +++
4 files changed, 238 insertions(+), 72 deletions(-)
--
2.34.1
