Re: [Xenomai-help] RTDM task blocks when connecting gdb to realtime task

[Jan Kiszka <jan.kiszka@domain.hid>]

Philippe Gerum wrote:
> On Fri, 2010-08-20 at 15:58 +0200, Jan Kiszka wrote:
>> Philippe Gerum wrote:
>>>>  However, terminating gdb and restarting app outside gdb
>>>> does make RTDM task resume execution. Before, the driver had to be reloaded.
>>>>
>>>> So gdb appears to be causing timer to block even if no breakpoint is set,
>>>> probably signals?
>>>>
>>> There is no reason for that. Sending "continue" to gdb is expected to
>>> unblock the timers, until the code is single-stepped again (e.g. after
>>> ^C or any breakpoint).
>> gdb silently intercepts a traced program for various reasons, e.g.
>> thread creation or library loading. Even if no user breakpoint is set,
>> the program may briefly be stopped nevertheless. If that happens
>> frequently enough, and every stop can add latencies to running timers...
> 
> We are talking about permanent freeze of timers, not transient (at least
> this is what I got from the ongoing discussion).

Yes, but what would happen if the interruption rate is higher than the
timer delay? Wouldn't we effectively end up with a permanent freeze?

Jan

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