Thread debugging and scheduling behaviour

[Hans Zuidam]

Hi,

When running a simple multi-threaded test outside and inside GDB we
see different scheduling behaviour.  This is on a Linux 2.4.20 system.

Specifically the test uses SCHED_FIFO scheduling and fixed priorities.
What we see is that when run outside GDB the higher priority threads
run first until they yield, while running in GDB (just a `run' no
breakpoints) causes low priority threads to run before high priority
ones.

Is this "expected" Linux behaviour or does it have something to do
with the thread handling in GDB?  Any pointers are greatly appreciated.

With kind regards,
Hans Zuidam
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