[AMD Official Use Only - AMD Internal Distribution Only]
>-----Original Message-----
>From: Kuehling, Felix <Felix.Kuehling@xxxxxxx>
>Sent: Tuesday, January 7, 2025 4:53 AM
>To: Deng, Emily <Emily.Deng@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
>Subject: Re: [PATCH] drm/amdkfd: Fix partial migrate issue
>
>
>On 2025-01-05 20:45, Deng, Emily wrote:
>> [AMD Official Use Only - AMD Internal Distribution Only]
>>
>>> -----Original Message-----
>>> From: Kuehling, Felix <Felix.Kuehling@xxxxxxx>
>>> Sent: Saturday, January 4, 2025 7:10 AM
>>> To: Deng, Emily <Emily.Deng@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
>>> Subject: Re: [PATCH] drm/amdkfd: Fix partial migrate issue
>>>
>>>
>>> On 2025-01-02 19:06, 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.Deng@xxxxxxx>
>>> Good catch. But I think it's still not quite right. See inline.
>>>
>>>
>>>> ---
>>>> 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;
>>>> 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)) {
>>> We should also check (migrate->src[i] & MIGRATE_PFN_MIGRATE) to catch
>>> only the pages that are ready to migrate (i.e. not already in device
>>> memory and not pinned by someone else).
>>>
>>> Regards,
>>> Felix
>>> The code " if (spage && !is_zone_device_page(spage)) {" is already checked
>whether the page could be migrated or not. Because after called migrate_vma_setup,
>for those pages couldn't be migrated it will be set to NULL.
>
>The page may be non-NULL. If the MIGRATE_PFN_MIGRATE is not set, the page
>could not be collected for migration by migrate_vma_setup and it should not be
>migrated. See
>https://elixir.bootlin.com/linux/v6.12.6/source/mm/migrate_device.c#L470
>
>Regards,
> Felix
Sorry, don't understand clearly. If a page couldn't be migrated, the src should be set NULL, if not, I think it is the migrate_vma_collect's bug. So could you point which code path
it will not be NULL.
>
>> Emily Deng
>> Best Wishes
>>
>>
>>>> @@ -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]);
>>>> }
>>>>
>>>> r = svm_migrate_copy_memory_gart(adev, src + i - j, dst + i -
>>>> j, j,
