Memory allocation with alignment > 64KB is disabled

[Alexandr-Konovalov]

Dear colleagues,

In urUSMHostAlloc() I see the code

  // L0 supports alignment up to 64KB and silently ignores higher values.
  // We flag alignment > 64KB as an invalid value.
  if (Align > 65536)
    return UR_RESULT_ERROR_INVALID_VALUE;

For old version of compute runtime, i.e. intel-level-zero-gpu 1.3.26516.18, such issue definitely exists, but after upgrade to recent intel-level-zero-gpu 1.3.29138.7 it disappeared.

Could you please make a limitation on the level of Unified Runtime less strict? Because right now sycl::aligned_alloc_shared() failed to work for alignment > 64KB.

[kbenzie]

I wonder if we could query the compute runtime verison and only perform this check for older version?

[pbalcer]

@kbenzie yea, that's probably the right approach. Ideally there'd be some API to query for capabilities.

Just curious, what is the use case you are thinking about for larger than a page alignment?

[Alexandr-Konovalov]

Just curious, what is the use case you are thinking about for larger than a page alignment?

It's used by BabelStream.