May in some cases improve performance when under memory pressure:
If a dedicated allocation is preferred, but the alloaction fails,
try to allocate memory from an already allocated chunk instead
of falling back to system memory right away.
The priority defines the importance of any given allocation being
resident in device-local memory rather than system memory, with
values between 0 (low) and 1 (high).
Suballocations will only work on chunks with the requested priority.
This ensures that high-priority allocations are reserved solely for
high-priority resources, and that high-priority resources will be
allocated from a high-priority memory chunk.
Instead of recreating the buffer view every single time the
underlying buffer gets invalidated, this keeps all buffer
views around until the object itself gets destroyed.
Reduces lock contention and slightly improves performance in games
that rely heavily on the buffer renaming mechanism if the lock
protecting the original free list was contested.
This is required for resource mapping on deferred contexts.
May also fix a potential synchronization issue where a buffer
could be mapped multiple times before the CS thread would mark
the physical buffer as used, which would result in invalid data.
This is the first step to optimizing buffer updates for applications
that frequently invalidate buffers. The goal is to reduce the number
of buffer allocations per frame and reduce the cost of invalidation.
