Re: Track down in-band switches

[Philippe Gerum <rpm@xenomai.org>]

Russell Johnson via Xenomai <xenomai@xenomai.org> writes:

> Hello,
>
>  
>
> I am currently working on porting my realtime threads in my app to EVL. I am
> using "evl ps -l" to track whether or not there are any in-band switches on
> my EVL threads. Is there any recommended tool or method for tracking down
> what specifically is causing the in-band switches on an EVL thread? 
>

There are two additional options provided by the health monitoring
interface [1], both enabled with [2]:

- using the legacy signal-based method (T_HMSIG), which sends SIGDEBUG
  (a Xenomai alias to SIGXCPU) to the thread which switches in-band,
  with the cause for switch available from the siginfo data.

- using the 'observable' interface of any EVL thread (T_HMOBS) to
  receive message-based notifications instead of signals. In this case,
  a thread can observe other threads, i.e. receive those
  notifications. [4] is a simple test which illustrates how to use this
  interface.

[1] https://evlproject.org/core/user-api/thread/#health-monitoring
[2] https://evlproject.org/core/user-api/thread/#evl_set_thread_mode
[3] https://evlproject.org/core/user-api/observable/#observable-thread
[4] https://source.denx.de/Xenomai/xenomai4/libevl/-/blob/master/tests/observable-hm.c

-- 
Philippe.