[PATCH] drm/amdkfd: ignore userptr NUMA auto balancing event

[Philip Yang]

NUMA auto balancing task_numa_work periodically change memory range
protection proto, in order to trigger CPU page hinting fault when CPU
access the memory later to check if that memory range need to migrate to
different NUMA node.

GPU can still access the memory after NUMA change the proto because the
memory is not moved yet, so it is safe to ignore the MMU notifier event
MMU_NOTIFY_PROTECTION_VMA to avoid unnecessary queue eviction and
restore.

Before NUMA auto balancing actually move the memory to different NUMA
node, driver will receive MMU notifier event MMU_NOTIFY_CLEAR to evict
the queues.

Signed-off-by: Philip Yang <Philip.Yang at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
index 828b5167ff12..dc4e2317dc31 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
@@ -106,6 +106,8 @@ static bool amdgpu_mn_invalidate_hsa(struct mmu_interval_notifier *mni,
 
 	if (!mmu_notifier_range_blockable(range))
 		return false;
+	if (range->event == MMU_NOTIFY_PROTECTION_VMA)
+		return true;
 
 	mutex_lock(&adev->notifier_lock);
 
-- 
2.17.1