diff options
author | Philip Yang <Philip.Yang@amd.com> | 2021-07-31 21:28:24 -0400 |
---|---|---|
committer | Alex Deucher <alexander.deucher@amd.com> | 2021-08-11 17:19:54 -0400 |
commit | eff8cbf096a735116cf6fad94d795652d9e0ff41 (patch) | |
tree | f30e5fe31f9b5fdc688ea9332dd50158d8784fcc | |
parent | f5bd523988c8c498ab18a35d729999894e4d2cf5 (diff) | |
download | linux-eff8cbf096a735116cf6fad94d795652d9e0ff41.tar.bz2 |
drm/amdkfd: AIP mGPUs best prefetch location for xnack on
For xnack on, if range ACCESS or ACCESS_IN_PLACE (AIP) by single GPU, or
range is ACCESS_IN_PLACE by mGPUs and all mGPUs connection on XGMI same
hive, the best prefetch location is prefetch_loc GPU. Otherwise, the best
prefetch location is always CPU because GPU does not have coherent
mapping VRAM of other GPUs even with large-BAR PCIe connection.
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
-rw-r--r-- | drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 35 |
1 files changed, 19 insertions, 16 deletions
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index 7df69b77bc5c..cffed408c8a7 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -2675,22 +2675,26 @@ svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size, return 0; } -/* svm_range_best_prefetch_location - decide the best prefetch location +/** + * svm_range_best_prefetch_location - decide the best prefetch location * @prange: svm range structure * * For xnack off: - * If range map to single GPU, the best acutal location is prefetch loc, which + * If range map to single GPU, the best prefetch location is prefetch_loc, which * can be CPU or GPU. * - * If range map to multiple GPUs, only if mGPU connection on xgmi same hive, - * the best actual location could be prefetch_loc GPU. If mGPU connection on - * PCIe, the best actual location is always CPU, because GPU cannot access vram - * of other GPUs, assuming PCIe small bar (large bar support is not upstream). + * If range is ACCESS or ACCESS_IN_PLACE by mGPUs, only if mGPU connection on + * XGMI same hive, the best prefetch location is prefetch_loc GPU, othervise + * the best prefetch location is always CPU, because GPU can not have coherent + * mapping VRAM of other GPUs even with large-BAR PCIe connection. * * For xnack on: - * The best actual location is prefetch location. If mGPU connection on xgmi - * same hive, range map to multiple GPUs. Otherwise, the range only map to - * actual location GPU. Other GPU access vm fault will trigger migration. + * If range is not ACCESS_IN_PLACE by mGPUs, the best prefetch location is + * prefetch_loc, other GPU access will generate vm fault and trigger migration. + * + * If range is ACCESS_IN_PLACE by mGPUs, only if mGPU connection on XGMI same + * hive, the best prefetch location is prefetch_loc GPU, otherwise the best + * prefetch location is always CPU. * * Context: Process context * @@ -2710,11 +2714,6 @@ svm_range_best_prefetch_location(struct svm_range *prange) p = container_of(prange->svms, struct kfd_process, svms); - /* xnack on */ - if (p->xnack_enabled) - goto out; - - /* xnack off */ if (!best_loc || best_loc == KFD_IOCTL_SVM_LOCATION_UNDEFINED) goto out; @@ -2724,8 +2723,12 @@ svm_range_best_prefetch_location(struct svm_range *prange) best_loc = 0; goto out; } - bitmap_or(bitmap, prange->bitmap_access, prange->bitmap_aip, - MAX_GPU_INSTANCE); + + if (p->xnack_enabled) + bitmap_copy(bitmap, prange->bitmap_aip, MAX_GPU_INSTANCE); + else + bitmap_or(bitmap, prange->bitmap_access, prange->bitmap_aip, + MAX_GPU_INSTANCE); for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) { pdd = kfd_process_device_from_gpuidx(p, gpuidx); |