[SYCLcompat] Add support for device attribute MAX_PITCH and ASYNC_ENGINE_COUNT

[the-slow-one]

CU_DEVICE_ATTRIBUTE_AYSNC_ENGINE_COUNT is associated with data transfer between device and host and kernel execution. This doesn't make sense in L0 backend and hence we return 0.

CU_DEVICE_ATTRIBUTE_MAX_PITCH return INT_MAX, indicating there is no limits! Intel GPU shows the same behavior too!

Signed-off-by: Deepak Raj H R

[GeorgeWeb]

Minor comment, otherwise syclcompat looks okay.

[JackAKirk]

CU_DEVICE_ATTRIBUTE_AYSNC_ENGINE_COUNT is associated with value 2 for bidirectional data transfer between host and device while executing the kernel and is associated to 1 in case of unidirectional data transfer and for no support of data transfer and parallel execution it's 0.

I may be misremembering, but I don't think the above is correct. IIRC querying CU_DEVICE_ATTRIBUTE_ASYNC_ENGINE_COUNT can return greater than 2 depending upon the NVLINK capabilities.

In any case I don't understand why you are always returning 0 for get_async_engine_count if you want to map it to the CU_DEVICE_ATTRIBUTE_ASYNC_ENGINE_COUNT device query?
The correct way of dealing with such device queries in a future-proof manner for all existing and future devices is to add a query in urDeviceGetInfo that calls cuDeviceGetAttribute using CU_DEVICE_ATTRIBUTE_ASYNC_ENGINE_COUNT https://github.com/oneapi-src/unified-runtime/blob/main/source/adapters/cuda/device.cpp#L41
and then calling this UR API via the sycl compat entry point using a mapped CU_DEVICE_ATTRIBUTE_ASYNC_ENGINE_COUNT query.

It may also have different mappings to other backends (e.g. AMD), and the call to urDeviceGetInfo allows such backends to return an appropriate value.

[GeorgeWeb]

Apart from the minor comment I left earlier, looking at this again, @JackAKirk is right that it seems a little strange to return 0 for all backends from get_async_engine_count when this should be correctly queried via device::get_info which calls into the respective backend query. I am still okay with this if the above stated may not be needed or if there's a plan to follow up with it in case it is needed. Thanks!

[JackAKirk]

Apart from the minor comment I left earlier, looking at this again, @JackAKirk is right that it seems a little strange to return 0 for all backends from get_async_engine_count when this should be correctly queried via device::get_info which calls into the respective backend query. I am still okay with this if the above stated may not be needed or if there's a plan to follow up with it in case it is needed. Thanks!

Apparently getting l0 path merged first is the priority, so I guess it is OK so long as there is an error message added that is returned if the backend in not l0?

Saying something like "This query is only currently supported on the L0 backend"

[GeorgeWeb]

Apart from the minor comment I left earlier, looking at this again, @JackAKirk is right that it seems a little strange to return 0 for all backends from get_async_engine_count when this should be correctly queried via device::get_info which calls into the respective backend query. I am still okay with this if the above stated may not be needed or if there's a plan to follow up with it in case it is needed. Thanks!

Apparently getting l0 path merged first is the priority, so I guess it is OK so long as there is an error message added that is returned if the backend in not l0?

Saying something like "This query is only currently supported on the L0 backend"

Sure okay, as long the associated commit message is also updated, I am okay with it. @the-slow-one
Also, I'll approve after addressing the INT_MAX -> std::numeric_limits<int>::max() feedback comment, unless there is an issue with this that I am not seeing, in which case do let me know. Thanks!

[ProGTX]

Saying something like "This query is only currently supported on the L0 backend"

@the-slow-one would it be possible to add something like that? Or maybe create an issue to track the creation of the UR query?

[the-slow-one]

Saying something like "This query is only currently supported on the L0 backend"

@the-slow-one would it be possible to add something like that? Or maybe create an issue to track the creation of the UR query?

@ProGTX I have added an issue #16663. I hope the details are sufficient. Please let me know.

[ProGTX]

Saying something like "This query is only currently supported on the L0 backend"

@the-slow-one would it be possible to add something like that? Or maybe create an issue to track the creation of the UR query?

@ProGTX I have added an issue #16663. I hope the details are sufficient. Please let me know.

Sounds good, thank you!