From: Philip Yang Philip.Yang@amd.com
[ Upstream commit 74097f9fd2f5ebdae04fcba59da345386415cbf3 ]
Move process queues cleanup to deferred work kfd_process_wq_release, to avoid potential deadlock circular locking warning:
WARNING: possible circular locking dependency detected the existing dependency chain (in reverse order) is: -> #2 ((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}: __flush_work+0x343/0x4a0 svm_range_list_lock_and_flush_work+0x39/0xc0 svm_range_set_attr+0xe8/0x1080 [amdgpu] kfd_ioctl+0x19b/0x600 [amdgpu] __x64_sys_ioctl+0x81/0xb0 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #1 (&info->lock#2){+.+.}-{3:3}: __mutex_lock+0xa4/0x940 amdgpu_amdkfd_gpuvm_acquire_process_vm+0x2e3/0x590 kfd_process_device_init_vm+0x61/0x200 [amdgpu] kfd_ioctl_acquire_vm+0x83/0xb0 [amdgpu] kfd_ioctl+0x19b/0x600 [amdgpu] __x64_sys_ioctl+0x81/0xb0 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #0 (&process->mutex){+.+.}-{3:3}: __lock_acquire+0x1365/0x23d0 lock_acquire+0xc9/0x2e0 __mutex_lock+0xa4/0x940 kfd_process_notifier_release+0x96/0xe0 [amdgpu] __mmu_notifier_release+0x94/0x210 exit_mmap+0x35/0x1f0 mmput+0x63/0x120 svm_range_deferred_list_work+0x177/0x2c0 [amdgpu] process_one_work+0x2a4/0x600 worker_thread+0x39/0x3e0 kthread+0x16d/0x1a0
Possible unsafe locking scenario:
CPU0 CPU1 ---- ---- lock((work_completion)(&svms->deferred_list_work)); lock(&info->lock#2); lock((work_completion)(&svms->deferred_list_work)); lock(&process->mutex);
Signed-off-by: Philip Yang Philip.Yang@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_process.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c index 19d4089a0b1c..3f2383db1b73 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c @@ -1111,6 +1111,15 @@ static void kfd_process_wq_release(struct work_struct *work) struct kfd_process *p = container_of(work, struct kfd_process, release_work);
+ kfd_process_dequeue_from_all_devices(p); + pqm_uninit(&p->pqm); + + /* Signal the eviction fence after user mode queues are + * destroyed. This allows any BOs to be freed without + * triggering pointless evictions or waiting for fences. + */ + dma_fence_signal(p->ef); + kfd_process_remove_sysfs(p); kfd_iommu_unbind_process(p);
@@ -1175,20 +1184,8 @@ static void kfd_process_notifier_release(struct mmu_notifier *mn, cancel_delayed_work_sync(&p->eviction_work); cancel_delayed_work_sync(&p->restore_work);
- mutex_lock(&p->mutex); - - kfd_process_dequeue_from_all_devices(p); - pqm_uninit(&p->pqm); - /* Indicate to other users that MM is no longer valid */ p->mm = NULL; - /* Signal the eviction fence after user mode queues are - * destroyed. This allows any BOs to be freed without - * triggering pointless evictions or waiting for fences. - */ - dma_fence_signal(p->ef); - - mutex_unlock(&p->mutex);
mmu_notifier_put(&p->mmu_notifier); }