[PATCH v2 0/5] drm/ttm, amdgpu: Introduce LRU bulk move functionality

Huang Rui ray.huang at amd.com
Mon Aug 13 06:52:06 UTC 2018


On Sun, Aug 12, 2018 at 10:12:56PM +0100, Mike Lothian wrote:
> Hi
> 
> I've been testing these patches over the weekend on my Tonga and Raven
> systems
> 
> Tested-by: Mike Lothian <mike at fireburn.co.uk>
> 

Thanks so much, Mike. I will add your tested-by in my next version.

Thanks,
Ray

> Cheers
> 
> Mike
> 
> On Fri, 10 Aug 2018 at 12:56 Huang Rui <ray.huang at amd.com> wrote:
> 
> > The idea and proposal is originally from Christian, and I continue to work
> > to
> > deliver it.
> >
> > Background:
> > amdgpu driver will move all PD/PT and PerVM BOs into idle list. Then move
> > all of
> > them on the end of LRU list one by one. Thus, that cause so many BOs moved
> > to
> > the end of the LRU, and impact performance seriously.
> >
> > Then Christian provided a workaround to not move PD/PT BOs on LRU with
> > below
> > patch:
> > "drm/amdgpu: band aid validating VM PTs"
> > Commit 0bbf32026cf5ba41e9922b30e26e1bed1ecd38ae
> >
> > However, the final solution should bulk move all PD/PT and PerVM BOs on
> > the LRU
> > instead of one by one.
> >
> > Whenever amdgpu_vm_validate_pt_bos() is called and we have BOs which need
> > to be
> > validated we move all BOs together to the end of the LRU without dropping
> > the
> > lock for the LRU.
> >
> > While doing so we note the beginning and end of this block in the LRU list.
> >
> > Now when amdgpu_vm_validate_pt_bos() is called and we don't have anything
> > to do,
> > we don't move every BO one by one, but instead cut the LRU list into
> > pieces so
> > that we bulk move everything to the end in just one operation.
> >
> > Test data:
> >
> > +--------------+-----------------+-----------+---------------------------------------+
> > |              |The Talos        |Clpeak(OCL)|BusSpeedReadback(OCL)
> >           |
> > |              |Principle(Vulkan)|           |
> >            |
> >
> > +------------------------------------------------------------------------------------+
> > |              |                 |           |0.319 ms(1k) 0.314 ms(2K)
> > 0.308 ms(4K) |
> > | Original     |  147.7 FPS      |  76.86 us |0.307 ms(8K) 0.310 ms(16K)
> >            |
> >
> > +------------------------------------------------------------------------------------+
> > | Orignial + WA|                 |           |0.254 ms(1K) 0.241 ms(2K)
> >           |
> > |(don't move   |  162.1 FPS      |  42.15 us |0.230 ms(4K) 0.223 ms(8K)
> > 0.204 ms(16K)|
> > |PT BOs on LRU)|                 |           |
> >            |
> >
> > +------------------------------------------------------------------------------------+
> > | Bulk move    |  163.1 FPS      |  40.52 us |0.244 ms(1K) 0.252 ms(2K)
> > 0.213 ms(4K) |
> > |              |                 |           |0.214 ms(8K) 0.225 ms(16K)
> >            |
> >
> > +--------------+-----------------+-----------+---------------------------------------+
> >
> > After test them with above three benchmarks include vulkan and opencl. We
> > can
> > see the visible improvement than original, and even better than original
> > with
> > workaround.
> >
> > Changes from V1 -> V2:
> > - Fix to missed the BOs in relocated/moved that should be also moved to
> > the end
> >   of LRU.
> >
> > Thanks,
> > Rui
> >
> > Christian König (2):
> >   drm/ttm: add helper structures for bulk moves on lru list
> >   drm/ttm: revise ttm_bo_move_to_lru_tail to support bulk moves
> >
> > Huang Rui (3):
> >   drm/ttm: add bulk move function on LRU
> >   drm/amdgpu: use bulk moves for efficient VM LRU handling (v2)
> >   drm/amdgpu: move PD/PT bos on LRU again
> >
> >  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 77
> > +++++++++++++++++++++++++--------
> >  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h |  4 ++
> >  drivers/gpu/drm/ttm/ttm_bo.c           | 78
> > +++++++++++++++++++++++++++++++++-
> >  include/drm/ttm/ttm_bo_api.h           | 16 ++++++-
> >  include/drm/ttm/ttm_bo_driver.h        | 28 ++++++++++++
> >  5 files changed, 184 insertions(+), 19 deletions(-)
> >
> > --
> > 2.7.4
> >
> > _______________________________________________
> > amd-gfx mailing list
> > amd-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/amd-gfx
> >

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