Re: [PATCH] drm/amdkfd: Use huge page size to check split svm range alignment

[Chen, Xiaogang]

On 11/11/2025 9:21 AM, Philip Yang wrote:

On 2025-11-10 15:30, Xiaogang.Chen wrote:
From: Xiaogang Chen <xiaogang.c...@amd.com>

Fixes: 7ef6b2d4b7e5 (drm/amdkfd: remap unaligned svm ranges that have 
split)

When split svm ranges that have been mapped using huge page should 
use huge
page size(2MB) to check split range alignment, not 
prange->granularity that
means migration granularity.

Signed-off-by: Xiaogang Chen <xiaogang.c...@amd.com>
---
  drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 521c14c7a789..3af85c232659 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1149,7 +1149,7 @@ svm_range_split_tail(struct svm_range *prange, 
uint64_t new_last,
        if (!r) {
          list_add(&tail->list, insert_list);
-        if (!IS_ALIGNED(new_last + 1, 1UL << prange->granularity))
+        if (!IS_ALIGNED(new_last + 1, 512))
we should check the original prange size is larger than 512 pages
          if (!IS_ALIGNED(new_last + 1, 512) && tail->last - 
prange->start >= 512)

ok, but should be following one?

  if (!IS_ALIGNED(tail->start, 512) || (tail->last - tail->start + 1)  
<  512)

list_add(&tail->update_list, remap_list);
      }
      return r;
@@ -1164,7 +1164,7 @@ svm_range_split_head(struct svm_range *prange, 
uint64_t new_start,
        if (!r) {
          list_add(&head->list, insert_list);
-        if (!IS_ALIGNED(new_start, 1UL << prange->granularity))
+        if (!IS_ALIGNED(new_start, 512))

if (!IS_ALIGNED(new_start, 512) && prange->last - head->start >= 512)

same for head case, should use this?

if (!IS_ALIGNED( head->start , 512) || ( head->last - head->start + 1)  
< 512)

Regards

Xiaogang

Regards,

Philip

list_add(&head->update_list, remap_list);
      }
      return r;