[SYCL][UR][L0 v2] import host ptr when SYCL_USM_HOSTPTR_IMPORT=1 and fix mapHostPtr #19297
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This matches v1 functionality and speeds up subsequent buffer map/unmap operations by making memory copy faster.
The logic for freeing mappedPtr was incorrect. We should only free the memory in unmapHostPtr if the pointer was allocated in mapHostPtr, not the other way around.
pbalcer
reviewed
Jul 4, 2025
Fixed. It seems that UR_MEM_FLAG_USE_HOST_POINTER does not have to be set when hostPtr is not null. In the legacy adapter this flag controlled whether to import the memory to USM or not but I don't see a reason not to do it in all cases. It seems that SYCL almost always sets UR_MEM_FLAG_USE_HOST_POINTER anyway (except in that one test) |
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Actually, I wonder why do we event support that combination (non-null hostPtr and no USE_HOST_PTR flag). OpenCL doesn't seem to allow this: https://registry.khronos.org/OpenCL/sdk/3.0/docs/man/html/clCreateBuffer.html |
pbalcer
approved these changes
Jul 17, 2025
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