5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Xiaogang Chen xiaogang.chen@amd.com
[ Upstream commit 7bfaa160caed8192f8262c4638f552cad94bcf5a ]
This patch fixes: 1: ref number of prange's svm_bo got decreased by an async call from hmm. When wait svm_bo of prange got released we shoul also wait prang->svm_bo become NULL, otherwise prange->svm_bo may be set to null after allocate new vram buffer.
2: During waiting svm_bo of prange got released in a while loop should reschedule current task to give other tasks oppotunity to run, specially the the workque task that handles svm_bo ref release, otherwise we may enter to softlock.
Signed-off-by: Xiaogang.Chen xiaogang.chen@amd.com Reviewed-by: Felix Kuehling Felix.Kuehling@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index 22a70aaccf13c..86135ca33e5be 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -433,11 +433,11 @@ svm_range_validate_svm_bo(struct amdgpu_device *adev, struct svm_range *prange)
/* We need a new svm_bo. Spin-loop to wait for concurrent * svm_range_bo_release to finish removing this range from - * its range list. After this, it is safe to reuse the - * svm_bo pointer and svm_bo_list head. + * its range list and set prange->svm_bo to null. After this, + * it is safe to reuse the svm_bo pointer and svm_bo_list head. */ - while (!list_empty_careful(&prange->svm_bo_list)) - ; + while (!list_empty_careful(&prange->svm_bo_list) || prange->svm_bo) + cond_resched();
return false; }