On 1/6/2025 8:02 PM, Deng, Emily wrote:
[AMD Official Use Only - AMD Internal Distribution Only]
*From:*Chen, Xiaogang <xiaogang.c...@amd.com>
*Sent:* Monday, January 6, 2025 11:27 PM
*To:* Deng, Emily <emily.d...@amd.com>; amd-gfx@lists.freedesktop.org
*Subject:* Re: [PATCH] drm/amdkfd: Fix partial migrate issue
On 1/2/2025 6:06 PM, Emily Deng wrote:
For partial migrate from ram to vram, the migrate->cpages is not
equal to migrate->npages, should use migrate->npages to check all needed
migrate pages which could be copied or not.
And only need to set those pages could be migrated to migrate->dst[i], or
the migrate_vma_pages will migrate the wrong pages based on the
migrate->dst[i].
Signed-off-by: Emily Deng<emily.d...@amd.com> <mailto:emily.d...@amd.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
index 4b275937d05e..5c96c2d425e3 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
@@ -278,7 +278,7 @@ svm_migrate_copy_to_vram(struct kfd_node *node, struct
svm_range *prange,
struct migrate_vma *migrate, struct dma_fence
**mfence,
dma_addr_t *scratch, uint64_t ttm_res_offset)
{
- uint64_t npages = migrate->cpages;
+ uint64_t npages = migrate->npages;
I agree this part.
struct amdgpu_device *adev = node->adev;
struct device *dev = adev->dev;
struct amdgpu_res_cursor cursor;
@@ -299,9 +299,6 @@ svm_migrate_copy_to_vram(struct kfd_node *node, struct
svm_range *prange,
struct page *spage;
dst[i] = cursor.start + (j << PAGE_SHIFT);
- migrate->dst[i] = svm_migrate_addr_to_pfn(adev, dst[i]);
- svm_migrate_get_vram_page(prange, migrate->dst[i]);
- migrate->dst[i] = migrate_pfn(migrate->dst[i]);
spage = migrate_pfn_to_page(migrate->src[i]);
if (spage && !is_zone_device_page(spage)) {
@@ -345,6 +342,9 @@ svm_migrate_copy_to_vram(struct kfd_node *node, struct
svm_range *prange,
} else {
j++;
}
+ migrate->dst[i] = svm_migrate_addr_to_pfn(adev, dst[i]);
+ svm_migrate_get_vram_page(prange, migrate->dst[i]);
+ migrate->dst[i] = migrate_pfn(migrate->dst[i]);
I think what current code misses here is that migrate->dst[i] should
match migrate->src[i]: migrate->dst[i](vram page) got set for page
that will be migrated from system ram, otherwise migrate->dst[i]
should be zero. Your change makes migrates->dst[i] not set though its
page has been migrated by svm_migrate_copy_memory_gart for the case
that cpages != npages, because you set migrate->dst[i] at end of loop
and use 'continue' after migration.
The page migration happens at svm_migrate_copy_memory_gart, not
migrate_vma_pages that migrates struct page meta-data from source
struct page to destination struct page and has mmu notification.
Regards
Xiaogang
The migrate->dst[i] default value is 0. The purpose of the change is
to match the migrate->dst[i] and migrate->src[i]. And for
svm_migrate_copy_to_vram, it only will call
svm_migrate_copy_memory_gart to copy those pages which need to be
migrated, for those don’t need migrate pages, it won’t call
svm_migrate_copy_memory_gart.
Yes, the issue here is we need match migrate->dst[i] and
migrate->src[i]: migrate->dst[i] need be set only when its correspondent
migrate->src[i] page will be migrated or the src page has dma address
setup by dma_map_page. Then why not set migrate->dst[i] at same time
when have dma_map_page for src page? That way will simplify the logic
and not need use amdgpu_res_next to jump vram cursor.
Regards
Xiaogang
}
r = svm_migrate_copy_memory_gart(adev, src + i - j, dst + i - j, j,
