[SYCL][L0] Use immediate commandlists.

[rdeodhar]

This change adds a mode where the plugin uses immediate commandlists instead of standard commandlists. The default remains standard commandlists. The new mode is selected by setting an environment variable.

Signed-off-by: Rajiv Deodhar [email protected]

[smaslov-intel]

I took a brief look and looks great overall!

The batching tests are, of course, expected to fail, and we need to:

1. Run them with batching forced
2. Add new test for immediate submission

Additionally, we need to

1. Make use of device-scope events (I suggest doing so in separate PR, and force all host-visible in this PR)
2. Measure perf impact to different HW (and chose presumably different defaults)
3. Document new option (in debug section)

[smaslov-intel]

There is existing _pi_context::ZeCommandListInit immediate command-list that we now use for buffer initialization. I think that can be changed to use the new infra instead.

[rdeodhar]

"There is existing _pi_context::ZeCommandListInit immediate command-list that we now use for buffer initialization. I think that can be changed to use the new infra instead."

That commandlist uses ZE_COMMAND_QUEUE_MODE_SYNCHRONOUS for immediate initialization. Other commandlists do not use this mode so are not directly usable.

[smaslov-intel]

That commandlist uses ZE_COMMAND_QUEUE_MODE_SYNCHRONOUS for immediate initialization. Other commandlists do not use this mode so are not directly usable.

True. Let's not touch it then.

[smaslov-intel]

This change switches from using ordinary commandlists to immediate commandlists.

It just add this mode, but doesn't switch to it by default, right? Please update the description.

[smaslov-intel]

LGTM