Commit c46ebb6a authored by Philip Yang's avatar Philip Yang Committed by Alex Deucher
Browse files

drm/amdkfd: set memory limit to avoid OOM with HMM enabled 



HMM migration alloc sizeof(struct page) on system memory for each VRAM
page, it is 1GB system memory reserved for 64GB VRAM. To avoid
application OOM, increase system memory used size based on VRAM size of
all GPUs, then application alloc memory will fail if system memory usage
reach the limit.

Signed-off-by: default avatarPhilip Yang <Philip.Yang@amd.com>
Reviewed-by: default avatarOak Zeng <Oak.Zeng@amd.com>
Reviewed-by: default avatarFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: default avatarFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 814ab993

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h

+1 −0
Original line number Diff line number Diff line
@@ -275,6 +275,7 @@ void amdgpu_amdkfd_gpuvm_init_mem_limits(void); 
void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,

				struct amdgpu_vm *vm);

void amdgpu_amdkfd_unreserve_memory_limit(struct amdgpu_bo *bo);

void amdgpu_amdkfd_reserve_system_mem(uint64_t size);

#else

static inline

void amdgpu_amdkfd_gpuvm_init_mem_limits(void)

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c

+5 −0
Original line number Diff line number Diff line
@@ -108,6 +108,11 @@ void amdgpu_amdkfd_gpuvm_init_mem_limits(void) 
		(kfd_mem_limit.max_ttm_mem_limit >> 20));

}



void amdgpu_amdkfd_reserve_system_mem(uint64_t size)

{

	kfd_mem_limit.system_mem_used += size;

}



/* Estimate page table size needed to represent a given memory size

 *

 * With 4KB pages, we need one 8 byte PTE for each 4KB of memory

drivers/gpu/drm/amd/amdkfd/kfd_migrate.c

+8 −0
Original line number Diff line number Diff line
@@ -57,6 +57,9 @@ static const struct dev_pagemap_ops svm_migrate_pgmap_ops = { 
	.migrate_to_ram		= svm_migrate_to_ram,

};



/* Each VRAM page uses sizeof(struct page) on system memory */

#define SVM_HMM_PAGE_STRUCT_SIZE(size) ((size)/PAGE_SIZE * sizeof(struct page))



int svm_migrate_init(struct amdgpu_device *adev)

{

	struct kfd_dev *kfddev = adev->kfd.dev;
@@ -93,6 +96,11 @@ int svm_migrate_init(struct amdgpu_device *adev) 
		return PTR_ERR(r);

	}



	pr_debug("reserve %ldMB system memory for VRAM pages struct\n",

		 SVM_HMM_PAGE_STRUCT_SIZE(size) >> 20);



	amdgpu_amdkfd_reserve_system_mem(SVM_HMM_PAGE_STRUCT_SIZE(size));



	pr_info("HMM registered %ldMB device memory\n", size >> 20);



	return 0;