[Intel-gfx] [PATCH 16/40] drm/i915: Pull scheduling under standalone lock

[Tvrtko Ursulin]

On 25/09/2018 09:19, Chris Wilson wrote:
> Quoting Tvrtko Ursulin (2018-09-24 12:19:39)
>>
>> On 19/09/2018 20:55, Chris Wilson wrote:
>>> diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
>>> new file mode 100644
>>> index 000000000000..910ac7089596
>>> --- /dev/null
>>> +++ b/drivers/gpu/drm/i915/i915_scheduler.c
>>> @@ -0,0 +1,377 @@
>>> +/*
>>> + * SPDX-License-Identifier: MIT
>>> + *
>>> + * Copyright © 2018 Intel Corporation
>>> + */
>>> +
>>> +#include <linux/mutex.h>
>>> +
>>> +#include "i915_drv.h"
>>> +#include "i915_request.h"
>>> +#include "i915_scheduler.h"
>>> +
>>> +static DEFINE_SPINLOCK(schedule_lock);
>>
>> Any good excuses to not put it into device private straight away?
> 
> It can't be per-device, since it will need to be global across devices
> as the dependency chains may cross devices and we will want to choose an
> optimal order globally. That's my goal here, at least.
> 
> At some point, the horror of scalability vs priority inversion must then
> be tackled. (But for now, I'd rather have priority inheritance and start
> from a position of good qos and build scalability on top.)

Hm.. questionable that we would want to break the isolation between 
devices, but more importantly too early to know. Struct mutex this 
replaces is certainly per device so I'd expect would had been an 
argument to keep that organisation. At least not change two things at 
once. Never mind, it is not a very important detail at the moment.

Regards,

Tvrtko