cpus_in_xmon questions

Anton Blanchard anton at samba.org
Wed Aug 27 10:27:31 EST 2003


> Also, what is cpus_in_xmon used for? In xmon/xmon.c, it looks like it's
> used to prevent a CPU from recursively entering xmon. What could cause
> that, and would an oops or some sort of message be better there? What
> prevents a UP CPU from doing the same thing?

That area of code should probably be looked over. Entering xmon
recursively is bad stuff but we should not lock up silently.

> In hvc_console.c, if any CPU is in xmon, the thread skips polling for
> any data. Why?

Because otherwise both hvc_console and xmon poll for characters. The
result is you get maybe every second character through to xmon and every
other gets sucked up by hvc_console running on another cpu.

Its a hack to use cpus_in_xmon, we should have something more generic so
kdb can do the right thing here too.


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