On 04/24/2018 12:14 PM, Eric W. Biederman wrote:
> Andrey Grodzovsky <andrey.grodzovsky at amd.com> writes:
>
>> If the ring is hanging for some reason allow to recover the waiting
>> by sending fatal signal.
>>
>> Originally-by: David Panariti <David.Panariti at amd.com>
>> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
>> ---
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 14 ++++++++++----
>> 1 file changed, 10 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>> index eb80edf..37a36af 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>> @@ -421,10 +421,16 @@ int amdgpu_ctx_wait_prev_fence(struct amdgpu_ctx *ctx, unsigned ring_id)
>>
>> if (other) {
>> signed long r;
>> - r = dma_fence_wait_timeout(other, false, MAX_SCHEDULE_TIMEOUT);
>> - if (r < 0) {
>> - DRM_ERROR("Error (%ld) waiting for fence!\n", r);
>> - return r;
>> +
>> + while (true) {
>> + if ((r = dma_fence_wait_timeout(other, true,
>> + MAX_SCHEDULE_TIMEOUT)) >= 0)
>> + return 0;
>> +
>> + if (fatal_signal_pending(current)) {
>> + DRM_ERROR("Error (%ld) waiting for fence!\n", r);
>> + return r;
>> + }
> It looks like if you make this code say:
> if (fatal_signal_pending(current) ||
> (current->flags & PF_EXITING)) {
> DRM_ERROR("Error (%ld) waiting for fence!\n", r);
> return r;
>> }
>> }
> Than you would not need the horrible hack want_signal to deliver signals
> to processes who have passed exit_signal() and don't expect to need
> their signal handling mechanisms anymore.
Let me clarify, the change in want_signal wasn't addressing this code
but hang in
drm_sched_entity_do_release->wait_event_killable, when you try to
gracefully terminate by waiting
for all job completions on the GPU pipe you process is using.
Andrey
>
> Eric
>
