On 2021-11-09 10:26 p.m., Felix
Kuehling wrote:
On 2021-11-09 6:04 p.m., Philip Yang wrote:
If unmapping partial range, the parent prange list op is update
notifier, child range list op is unmap range, need check child range to
set drain retry fault flag.
Signed-off-by: Philip Yang <Philip.Yang@xxxxxxx>
I think this could be simplified by simply setting svms->drain_pagefaults in svm_range_unmap_from_cpu. The mmap lock ensures that this is serialized with the deferred list worker reading and clearing svms->drain_pagefaults. You can also use READ_ONCE and WRITE_ONCE to be safe.
Good idea, change will be in v2 patch.
Thanks,
Philip
Regards,
Felix
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 77239b06b236..64f642935600 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2049,8 +2049,19 @@ svm_range_add_list_work(struct svm_range_list *svms, struct svm_range *prange,
* before the range is freed to avoid straggler interrupts on
* unmapped memory causing "phantom faults".
*/
- if (op == SVM_OP_UNMAP_RANGE)
+ if (op == SVM_OP_UNMAP_RANGE) {
+ pr_debug("set range drain_pagefaults true\n");
svms->drain_pagefaults = true;
+ } else {
+ struct svm_range *pchild;
+
+ list_for_each_entry(pchild, &prange->child_list, child_list)
+ if (pchild->work_item.op == SVM_OP_UNMAP_RANGE) {
+ pr_debug("set child drain_pagefaults true\n");
+ svms->drain_pagefaults = true;
+ }
+ }
+
/* if prange is on the deferred list */
if (!list_empty(&prange->deferred_list)) {
pr_debug("update exist prange 0x%p work op %d\n", prange, op);
