[SYCL][XPTI] Memory Transfer event instrumentation

[and7mw]

Hello!

MemCpyCommand::emitInstrumentationData():

llvm/sycl/source/detail/scheduler/commands.cpp

Lines 1342 to 1347 in 134618f

	xpti::addMetadata(CmdTraceEvent, "copy_from",
	reinterpret_cast<size_t>(
	getSyclObjImpl(MSrcQueue->get_device()).get()));
	xpti::addMetadata(
	CmdTraceEvent, "copy_to",
	reinterpret_cast<size_t>(getSyclObjImpl(MQueue->get_device()).get()));

and
MemCpyCommandHost::emitInstrumentationData():

llvm/sycl/source/detail/scheduler/commands.cpp

Lines 1524 to 1529 in 134618f

	xpti::addMetadata(CmdTraceEvent, "copy_from",
	reinterpret_cast<size_t>(
	getSyclObjImpl(MSrcQueue->get_device()).get()));
	xpti::addMetadata(
	CmdTraceEvent, "copy_to",
	reinterpret_cast<size_t>(getSyclObjImpl(MQueue->get_device()).get()));

add copy_from and copy_to metadata as pointer to device.

Is it expected behaviour?

I would expect that device id or device name should be add.

This behaviour was introduced after merge this PR: #4998
@alexbatashev could you take a look please?

Environment:

• DPC++ version: 4043dda

Question: Is there any way knowing the device ID to get its name?

[alexbatashev]

That is expected. Pointer to device object is used as a device ID. Per the specification, root devices are unique to platform, and handles must always be the same.

[and7mw]

@alexbatashev I added simple patch for these emmiters to save device ids which return by deviceToID function.

xpti::addMetadata(CmdTraceEvent, "copy_from_id", deviceToID(MSrcQueue->get_device())); xpti::addMetadata(CmdTraceEvent, "copy_to_id", deviceToID(MQueue->get_device()));

And as I can see they are different from pointer values:

1665000850375537066 : name=Memory Transfer (Copy)[0x2427c50] cpu= 0 event_id= 12637246
copy_to_id : 0
copy_from_id : 29751312
sycl_device_type : HOST
sycl_device : 0
copy_from : 40824656
sycl_device_name : SYCL host device
memory_object : 37911632
copy_to : 30956464
---[Source file:line no] (null):-1

Is it also expected?
If yes, why in all other places XPTI return device ID (sycl_device) as value returned by deviceToID function?
Example:

llvm/sycl/source/detail/scheduler/commands.cpp

Lines 1516 to 1517 in 134618f

	xpti::addMetadata(CmdTraceEvent, "sycl_device",
	deviceToID(MQueue->get_device()));

[alexbatashev]

@and7mw you're probably right, this occurence should use deviceToID as well

[tovinkere]

@and7mw Thank you for pointing out the inconsistency. Since this is metadata, should "copy_from" and "copy_to" have deviceID or device name? Currently changing the metadata to point to deviceID obtained from deviceToID() helper.

[and7mw]

@tovinkere I guess that for tool developer enough to "copy_from" and "copy_to" have device name. However may appear problem in case if several different devices will have the same name (not sure that it's possible in DPC++).