Re: [PATCH] watchdog: perform all-CPU backtrace in case of hard lockup

[Aaron Tomlin]

On Thu 2015-10-01 09:45 +0200, Jiri Kosina wrote:
> That should be fine. Worst case scenario is hardlockup and softlockup 
> trigerring 'in parallel' on different CPUs, and all-cpu backtrace being 
> triggered twice.
> 
> Frankly, I've never seen this happen in practice (hardlockup and 
> softlockup triggering at different CPUs at the very same time).
> 
> We could possibly make a global 'all_cpus_dump_in_progress' flag so that 
> we guarantee only one stream of dumps, but we'd need to convert everybody 
> using this facility (e.g. RCU stall detector, and whoever else) to be 
> aware of it as well, otherwise it wouldn't make too much sense.
> 
> Something to add to TODO I guess.

This could indeed be worth further investigation.


-- 
Aaron Tomlin
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