[igt-dev] [PATCH i-g-t 10/10] tests/i915/exec_fence: add timeline fence tests

[Lionel Landwerlin]

On 02/08/2019 12:11, Chris Wilson wrote:
> Quoting Lionel Landwerlin (2019-08-02 10:03:59)
>> On 31/07/2019 23:33, Chris Wilson wrote:
>>> Quoting Lionel Landwerlin (2019-07-25 11:30:34)
>>> You could move this to a second context and avoid the differentiation
>>> between engines:
>>>
>>>        fence.flags = I915_EXEC_FENCE_WAIT;
>>>        execbuf.rsvd1 = gem_context_create(fd);
>>>
>>>        n = 0;
>>>        for_each_engine(fd, engine) {
>>>                obj.handle = gem_create(fd, 4096);
>>>                gem_write(fd, obj.handle, 0, &bbe, sizeof(bbe));
>>>
>>>                /* Unsynchronised will execute ahead of the blockage */
>>>                execbuf.flags = engine;
>>>                execbuf.cliprects_ptr = 0;
>>>                gem_execbuf(fd, &execbuf);
>>>                gem_sync(fd, obj.handle);
>>
>> Not quite sure this ends up blocking on engine=1.
> It's a different context, it's allowed to execute ahead of the spinner
> when the spinner exceeds its timeslice -- so long as preemption is
> enabled on the spinner. If not, that's kernel bug.
> -Chris
>
Hmm... modifying the existing test_syncobj_wait() to do the same leads 
to a deadlock.

That's on a stable 5.0 kernel, so that appears unrelated to my timeline 
semaphore changes.


-Lionel