When compute preemption is available we schedule more work which is more
efficient. However the CUDA driver appears to be incorrectly reporting this as
unavailable, even though it should be supported starting with Windows 10 1803
and Pascal and Turing (10x0 and 20x0) graphics cards.
This reduces render time by about a 25% difference on our benchmark scenes. On
Linux compute preemption appears to be reported correctly.
The issue was introduced by a Threadripper2 commit back in
ce927e15e0. This boils down to threads inheriting affinity
from the parent thread. It is a question how this slipped
through the review (we definitely run benchmark round).
Quick fix could have been to always set CPU group affinity
in Cycles, and it would work for Windows. On other platforms
we did not have CPU groups API finished.
Ended up making Cycles aware of NUMA topology, so now we
bound threads to a specific NUMA node. This required adding
an external dependency to Cycles, but made some code there
shorter.
Currently for windows only, this is an initial commit towards native
support of NUMA.
Current commit makes it so Cycles will use all logical processors on
Windows running on system with more than 64 threads.
Reviewers: juicyfruit, dingto, lukasstockner97, maiself, brecht
Subscribers: LazyDodo
Differential Revision: https://developer.blender.org/D2049
The title says it all actually, the idea is to make Cycles
only requiring Boost via 3rd party dependencies like OIIO
and OSL.
So now there are only few places which still uses Boost:
- Foreach, function bindings and threading primitives.
Those we can easily get rid with C++11 bump (which seems
inevitable sooner or later if we'll want ot use newer
LLVM for OSL),
- Networking devices
There's no quick solution for those currently, but there
are some patches around which improves serialization.
Reviewers: juicyfruit, mont29, campbellbarton, brecht, dingto
Reviewed By: brecht, dingto
Differential Revision: https://developer.blender.org/D1764
