On 04.08.2014 17:56, Maarten Lankhorst wrote:
> op 04-08-14 10:42, Michel D?nzer schreef:
>> On 02.08.2014 02:07, Maarten Lankhorst wrote:
>>> On 01-08-14 16:13, Michel D?nzer wrote:
>>>> On 01.08.2014 19:12, Maarten Lankhorst wrote:
>>>>> On 01-08-14 10:27, Michel D?nzer wrote:
>>>>>> On 01.08.2014 00:34, Maarten Lankhorst wrote:
>>>>>>> @@ -357,14 +360,20 @@ int radeon_gem_wait_idle_ioctl(struct drm_device
>>>>>>> *dev, void *data,
>>>>>>> struct drm_radeon_gem_wait_idle *args = data;
>>>>>>> struct drm_gem_object *gobj;
>>>>>>> struct radeon_bo *robj;
>>>>>>> - int r;
>>>>>>> + int r = 0;
>>>>>>> + long ret;
>>>>>>>
>>>>>>> gobj = drm_gem_object_lookup(dev, filp, args->handle);
>>>>>>> if (gobj == NULL) {
>>>>>>> return -ENOENT;
>>>>>>> }
>>>>>>> robj = gem_to_radeon_bo(gobj);
>>>>>>> - r = radeon_bo_wait(robj, NULL, false);
>>>>>>> + ret = reservation_object_wait_timeout_rcu(robj->tbo.resv, true,
>>>>>>> true, 30 * HZ);
>>>>>>> + if (ret == 0)
>>>>>>> + r = -EBUSY;
>>>>>>> + else if (ret < 0)
>>>>>>> + r = ret;
>>>>>>> +
>>>>>>> /* callback hw specific functions if any */
>>>>>>> if (rdev->asic->ioctl_wait_idle)
>>>>>>> robj->rdev->asic->ioctl_wait_idle(rdev, robj);
>>>>>> Heads up, this conflicts with
>>>>>> http://lists.freedesktop.org/archives/dri-devel/2014-August/065255.html
>>>>>> which passes a non-NULL second argument to radeon_bo_wait() to get the
>>>>>> BO's current domain.
>>>>> Ok, I will fix it up and resend it later.
>>>>>
>>>>> Does it matter if I grab the current domain without grabbing the lock
>>>>> here? Because it doesn't matter if it sees the old or new domain, it
>>>>> could have been changed after returning too.
>>>> It should be the domain where the BO is located when the fence we are
>>>> waiting for here signals.
>>> Could we compare domain before and after the rcu wait, and retry
>>> waiting if they're different, and the new one is VRAM? (eg eviction
>>> happened) That should prevent needing to lock the bo.
>> Eviction normally only happens from VRAM, not to VRAM. :) So if you know
>> whether the domain is VRAM or not after the wait, you can just proceed
>> accordingly, I don't see why you'd need to wait again.
> Because in the worst case you didn't wait on the fence that started
> the eviction, but one before it. ;-)
I'm afraid you've lost me. Can you determine the domain that
radeon_bo_wait() would have returned?
--
Earthling Michel D?nzer | http://www.amd.com
Libre software enthusiast | Mesa and X developer
