[Intel-gfx] [PATCH 2/2] drm/i915: Fix timeout handling in i915_gem_shrinker_vmap

[Tvrtko Ursulin]

On 09/01/2019 14:23, Chris Wilson wrote:
> Quoting Tvrtko Ursulin (2019-01-09 14:12:47)
>> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>>
>> The code tries to grab struct mutex for 5ms every time the unlocked GPU
>> idle wait succeeds. But the GPU idle wait itself is practically unbound
>> which means the 5ms timeout might not be honoured.
> 
> The arbitrary timeout is merely advisory. If we hang, we get to recover
> everything we can!

You mean if we hang, eg. take more than 5ms to idle, the function bails 
out on the 5ms timeout check, failing to take the lock and free anything? ;)

Regards,

Tvrtko