ROCm (Rocgdb debugger) use queues to pass debug commands?

[It's Me]

Hi Tony , 

I appreciate the reply , thanks . 

So just to confirm the commands are not encapsulated in a packet and pushed into queues in HSA AQL queues . 

Can you please give a high level path for setting a breakpoint from user land to the GPU ( how the flow happen through the software stack ) 

Also if there is not much trouble can you also provide any APIs for passing a breakpoint . I looked through rocgdb / rocgdb driver code / ROCm API .. and the clear path is not clear for me .. 

Again thanks a lot for the help and the reply . Appreciated 

> On Feb 1, 2021, at 12:24 PM, Tye, Tony <Tony.Tye@amd.com> wrote:
> 
> [AMD Official Use Only - Internal Distribution Only]
> 
> rocgdb uses a driver that provides an ioctl interface that is similar in concept to what the ptrace and waitpid do for a CPU. There is a Debugger API library that uses the ioctl interface to provide an general way to control the GPU threads. There is a rocm target that is part of gdb that uses the Debugger ABI to allow GPU threads to be controlled just like CPU threads. All the code is open source.
> 
> Thanks,
> -Tony
> 
> -----Original Message-----
> From: Gdb <gdb-bounces@sourceware.org> On Behalf Of It's Me via Gdb
> Sent: Monday, February 1, 2021 3:18 PM
> To: gdb@sourceware.org
> Subject: ROCm (Rocgdb debugger) use queues to pass debug commands?
> 
> [CAUTION: External Email]
> 
> Hi ,
> 
> In a heterogenous environment , how ROCm / rocgdb pass its debug commands ( example : breakpoint command) to the target ( Example a GPU) . Does the debugger queue it’s debug commands using HSA queues ? If that’s not that case how ?
> 
> What is the role of the driver in this case .
> 
> Thanks