Added roundup_bypass_threshold_mb knobs to the PyTorch Caching Allocator (#85940)
Summary:
Added an additional roundup knob( ``roundup_bypass_threshold_mb``) to bypass rounding the requested allocation size, for allocation requests larger than the threshold value (in MB). This can help reduce the memory footprint when making large allocations that are expected to be persistent or have a large lifetime.
Differential Revision: D39868104
Pull Request resolved: https://github.com/pytorch/pytorch/pull/85940
Approved by: https://github.com/zdevito
