[PATCH 0/9] drm/i915/gvt: Refine the gtt shadowing

[Zhi Wang]

Besides, the right way of thinking to figure out the problem is we have 
to know the right direction, right? If we think we cannot do this 
because of efforts and time, like what you said, the customer might 
enable it, then we got challenged by Linus. I mean if the situation you 
describe really happens, it means we *didn't* do a good job to implement 
the memory shrinker. It *doesn't* mean the memory shrinker is the wrong 
direction. You see they are two different problems, one is practical, 
one is direction. Please do figure out the difference between *two* 
problems.

Thanks,
Zhi.

On 12/25/17 18:45, Zhi Wang wrote:
> Yes. But we need a correct re-claim path even the customer will report 
> it right?
> 
> Thanks,
> Zhi.
> 
> On 12/25/17 18:35, Du, Changbin wrote:
>> On Mon, Dec 25, 2017 at 06:22:47PM +0800, Zhi Wang wrote:
>>> I think it's a good idea because i915 has done that already and the 
>>> current
>>> shadow page reclaim path is actually just a simple workaround. The 
>>> right way
>>> to re-claim pages is from memory shrinker. For being challenged, I think
>>> it's OK because the memory shrinker will only be registered when GVT is
>>> enabled.
>>>
>> Even though the shrinker can only be enabled if GVTg is active, but 
>> the custom
>> can report such bug to mm mailist. Some mechanism that expose memory 
>> management
>> control to out of VM subsystem already be asked by Linus several times.
>>
>>>
>>> On 12/25/17 18:10, Du, Changbin wrote:
>>>> On Mon, Dec 25, 2017 at 06:02:21PM +0800, Zhi Wang wrote:
>>>>> BTW: Since we allocate a lot of pages from system memory, we might 
>>>>> need a
>>>>> memory shrinker here. If you are interested, you can ask Hang to 
>>>>> add an task
>>>>> item for you in the next Q.
>>>> It is not a good idea to do this at device driver.(at least not 
>>>> prefored).
>>>> Because we need be very careful since it is called from Linux VM 
>>>> directly.
>>>> If GVTg's bug breaks VM we will be challenged by Linus.
>>>>> Actually I think splitting ppgtt and ggtt in names is also a good 
>>>>> idea.The
>>>>> history I can remember is Kevin wants they looks the same from high 
>>>>> level
>>>>> calls during the patch of BDW enabling. In the first patch series 
>>>>> they were
>>>>> separated, also another APIs like *get_mm_*.
>>>>>
>>>>> Thanks,
>>>>> Zhi.
>>>>>
>>>>> On 12/25/17 17:11, changbin.du at intel.com wrote:
>>>>>> From: Changbin Du <changbin.du at intel.com>
>>>>>>
>>>>>> This is the first part of patch set "drm/i915/gvt: Add support for 
>>>>>> huge gtt (2M/64K)".
>>>>>> The GTT related code are refined. I just need a clean code base to 
>>>>>> add new
>>>>>> feature.
>>>>>>
>>>>>> patch #1 and #7 are fat patch, please take care.
>>>>>>
>>>>>> Changbin Du (9):
>>>>>>      drm/i915/gvt: Rework shadow graphic memory management code
>>>>>>      drm/i915/gvt: Add verbose gtt shadow logs
>>>>>>      drm/i915/gvt: Rename ggtt related functions to be more specific
>>>>>>      drm/i915/gvt: Factor out
>>>>>>        intel_vgpu_{get_or_create_ppgtt_mm,find_destroy_ppgtt_mm} 
>>>>>> interfaces
>>>>>>      drm/i915/gvt: Use standard pte bit definition
>>>>>>      drm/i915/gvt: Refine pte shadowing process
>>>>>>      drm/i915/gvt: Rework shadow page management code
>>>>>>      drm/i915/gvt: Manage shadow pages with radix tree
>>>>>>      drm/i915/gvt: Define PTE addr mask with GENMASK_ULL
>>>>>>
>>>>>>     drivers/gpu/drm/i915/gvt/Makefile     |    2 +-
>>>>>>     drivers/gpu/drm/i915/gvt/gtt.c        | 1427 
>>>>>> +++++++++++++++------------------
>>>>>>     drivers/gpu/drm/i915/gvt/gtt.h        |  182 ++---
>>>>>>     drivers/gpu/drm/i915/gvt/gvt.c        |    2 +-
>>>>>>     drivers/gpu/drm/i915/gvt/gvt.h        |    2 +
>>>>>>     drivers/gpu/drm/i915/gvt/handlers.c   |   18 +-
>>>>>>     drivers/gpu/drm/i915/gvt/mmio.c       |    9 +-
>>>>>>     drivers/gpu/drm/i915/gvt/mpt.h        |   36 +-
>>>>>>     drivers/gpu/drm/i915/gvt/page_track.c |  181 +++++
>>>>>>     drivers/gpu/drm/i915/gvt/page_track.h |   54 ++
>>>>>>     drivers/gpu/drm/i915/gvt/scheduler.c  |   48 +-
>>>>>>     drivers/gpu/drm/i915/gvt/trace.h      |   38 +-
>>>>>>     drivers/gpu/drm/i915/gvt/vgpu.c       |    1 +
>>>>>>     13 files changed, 1002 insertions(+), 998 deletions(-)
>>>>>>     create mode 100644 drivers/gpu/drm/i915/gvt/page_track.c
>>>>>>     create mode 100644 drivers/gpu/drm/i915/gvt/page_track.h
>>>>>>
>>>>> _______________________________________________
>>>>> intel-gvt-dev mailing list
>>>>> intel-gvt-dev at lists.freedesktop.org
>>>>> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
>>>
>>