[Bug 11674] Dual-core unsupported in WoW and SC2

[wine-bugs at winehq.org]

http://bugs.winehq.org/show_bug.cgi?id=11674

--- Comment #267 from Henri Verbeet <hverbeet at gmail.com> 2012-12-21 13:45:08 CST ---
(In reply to comment #266)
> Thanks for your interest; I'm sorry for the confusion, I didn't realize Stefan
> didn't keep you in the loop following our discussion on that topic. The point I
> was making is that BufferSubData inherently maps better to dynamic buffer
> workloads than MapBuffer-based updating in threaded usecases. Since
> BufferSubData requests can be immediately queued in-band in both commands
> streams, overhead is kept at a minimum and maximal GPU throughput can be
> achieved.
It doesn't strike me as something that's really inherent in the API, just the
specific implementation NVIDIA has. You'd have a point for D3D "static" buffers
that would require a synchronized map, but then those aren't really supposed to
be modified after they're initially created. (And implicitly that means they're
only supposed to be mapped before they're used in any draws, so you should only
ever potentially have to wait for the upload to finish before starting a draw,
once.) D3D "dynamic" buffers end up using either GL_MAP_UNSYNCHRONIZED_BIT or
GL_MAP_INVALIDATE_BUFFER_BIT on glMapBufferRange(), and shouldn't require
synchronization with the command stream at all; it's the application's
responsibility to ensure all accesses are safe.

> Stefan pointed out that memory usage was a big concern for Wine, and
The issue I suspect he's referring to is more about address space than actual
memory usage. Regardless, although that consideration does play a role, the
main consideration for me is that changing the code here would mean either
potentially making things worse for other drivers in order to make things
better for NVIDIA, or adding a special codepath for NVIDIA somewhere that's
going to bitrot or increase maintenance costs. While the latter at least isn't
entirely out of the question, it would require some solid justification.

-- 
Configure bugmail: http://bugs.winehq.org/userprefs.cgi?tab=email
Do not reply to this email, post in Bugzilla using the
above URL to reply.
------- You are receiving this mail because: -------
You are watching all bug changes.