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): 552.36049107142857142857,
.71943789893868318799
Average migrate 64K cpu time (us, percentage): 24.97767857142857142857,
.34789908128526791960
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
Sending as an RFC as there appears to be intermittent memory corruptions
when running xe_exec_system_allocator that need to be tracked down.
Matt
Matthew Brost (2):
drm/gpusvm: Use new dma-map IOVA alloc, link, and sync API in GPU SVM
drm/pagemap: Use new dma-map IOVA alloc, link, and sync API for DRM
pagemap
drivers/gpu/drm/drm_gpusvm.c | 63 +++++++++++-----
drivers/gpu/drm/drm_pagemap.c | 135 ++++++++++++++++++++++++++--------
include/drm/drm_gpusvm.h | 3 +
3 files changed, 152 insertions(+), 49 deletions(-)
--
2.34.1
