On 12/11/2024 11:30 PM, Zhu Lingshan wrote:
On 12/12/2024 12:19 PM, Felix Kuehling wrote:
On 2024-12-11 22:06, Zhu Lingshan wrote:
kfd_process_wq_release() signals eviction fence by
dma_fence_signal() which wanrs if dma_fence
is NULL.
That's news to me. Looking at the dma_fence_signal implementation on
amd-staging-drm-next, it just silently returns -EINVAL if the fence pointer is
NULL. I see the same in Linux
6.12.4:https://elixir.bootlin.com/linux/v6.12.4/source/drivers/dma-buf/dma-fence.c#L467
Which branch are you on?
Linus tree, latest master branch, tag v6.13-rc2
https://github.com/torvalds/linux/blob/master/drivers/dma-buf/dma-fence.c#L467
which is introduced by
https://github.com/torvalds/linux/commit/967d226eaae8e40636d257bf8ae55d2c5a912f58
It is new. I did not see it from AMD kernel either.
Previously I wanted put following dma_fence_put(ef) together with
dma_fence_signal(ef) :
+ if (ef) {
+ dma_fence_signal(ef);
+ dma_fence_put(ef)
+ }
That seems neater.
Regards
Xiaogang
Thanks
Lingshan
Regards,
Felix
kfd_process->ef is initialized by kfd_process_device_init_vm()
through ioctl. That means the fence is NULL for a new
created kfd_process, and close a kfd_process right
after open it will trigger the warning.
This commit conditionally signals the eviction fence
in kfd_process_wq_release() only when it is available.
[ 503.660882] WARNING: CPU: 0 PID: 9 at drivers/dma-buf/dma-fence.c:467
dma_fence_signal+0x74/0xa0
[ 503.782940] Workqueue: kfd_process_wq kfd_process_wq_release [amdgpu]
[ 503.789640] RIP: 0010:dma_fence_signal+0x74/0xa0
[ 503.877620] Call Trace:
[ 503.880066] <TASK>
[ 503.882168] ? __warn+0xcd/0x260
[ 503.885407] ? dma_fence_signal+0x74/0xa0
[ 503.889416] ? report_bug+0x288/0x2d0
[ 503.893089] ? handle_bug+0x53/0xa0
[ 503.896587] ? exc_invalid_op+0x14/0x50
[ 503.900424] ? asm_exc_invalid_op+0x16/0x20
[ 503.904616] ? dma_fence_signal+0x74/0xa0
[ 503.908626] kfd_process_wq_release+0x6b/0x370 [amdgpu]
[ 503.914081] process_one_work+0x654/0x10a0
[ 503.918186] worker_thread+0x6c3/0xe70
[ 503.921943] ? srso_alias_return_thunk+0x5/0xfbef5
[ 503.926735] ? srso_alias_return_thunk+0x5/0xfbef5
[ 503.931527] ? __kthread_parkme+0x82/0x140
[ 503.935631] ? __pfx_worker_thread+0x10/0x10
[ 503.939904] kthread+0x2a8/0x380
[ 503.943132] ? __pfx_kthread+0x10/0x10
[ 503.946882] ret_from_fork+0x2d/0x70
[ 503.950458] ? __pfx_kthread+0x10/0x10
[ 503.954210] ret_from_fork_asm+0x1a/0x30
[ 503.958142] </TASK>
[ 503.960328] ---[ end trace 0000000000000000 ]---
Signed-off-by: Zhu Lingshan<lingshan....@amd.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_process.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index 87cd52cf4ee9..47d36f43ee8c 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -1159,7 +1159,8 @@ static void kfd_process_wq_release(struct work_struct
*work)
*/
synchronize_rcu();
ef = rcu_access_pointer(p->ef);
- dma_fence_signal(ef);
+ if (ef)
+ dma_fence_signal(ef);
kfd_process_remove_sysfs(p);
