[Skiboot] [PATCH 0/2] direct-controls: p9 stop/cont fixes

Stewart Smith stewart at linux.ibm.com
Mon May 7 03:30:44 AEST 2018


Nicholas Piggin <npiggin at gmail.com> writes:
> This is unchanged since the RFC, passed some testing: `pdbg stop`
> a thread, then enter xmon in the host which cases it to NMI IPI
> all other CPUs. Result now is that it skips the stopped thread and
> it simply doesn't make it into xmon. pdbg cont resumes as normal,
> (but it looks like the thread doesn't receive its doorbell to get
> into xmon). Sending it a sreset with pdbg kicks it into xmon, and
> then resuming from xmon seems to result in the system recovering
> fine.
>
> Without this patch, the thread will be given the sreset, which
> can have undefined consequences if we're currently ramming or
> in some other stat. At best it will kick the thread out of quiesce
> and we lose our pdbg debugging session, at worst probably checkstop
> the box.
>
> These fixes should not affect non-error paths, or fix the timeout
> setting speial wakeup, or other errors we've often seen.

Cheers, series merged to master as of 0e27cc8410e22b6400f3e709697eb51c7d02b289.

we should possibly get some testing going in op-test of using pdbg from
the bmc and that generally being something we keep working.

-- 
Stewart Smith
OPAL Architect, IBM.



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