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Re: associative array synchronization question
On 07/20/2012 01:37 PM, Nicholas Murphy wrote:
> What does it mean that you "sometimes" fail to take a lock? Do you
> just skip executing the probe if you determine that you can't get the
> lock?
The only failure is from contention. We will spin-and-wait for a lock
to free up for a small time, but if it's too busy on other cpus, we'll
eventually give up. That's "sometimes", but hopefully rare. :)
And yes, if we can't get all necessary locks, that probe handler will be
skipped altogether.
You can find a bit more about this on the wiki:
http://sourceware.org/systemtap/wiki/TipSkippedProbesOptimization
Josh