lockless file descriptor lookup

Ed Schouten ed at 80386.nl
Tue May 12 16:59:51 UTC 2009

Hello Jeff,

* Jeff Roberson <jroberson at jroberson.net> wrote:
> Once the file descriptor is resolved, we verify the path via the  
> descriptor table once more to ensure that it has not changed.  At this  
> point, we have a valid reference or we drop an invalid reference and  
> retry.

It's nice to see someone stepped up to implement this. Just out of
curiosity, have you done any benchmarks to see how many percent of the
time a thread needs more than one attempt to obtain a valid reference on
a common workload?

Maybe it would be nice for diagnostic purposes to add two sysctls to
obtain the amount of successful and unsuccessful attempts.

 Ed Schouten <ed at 80386.nl>
 WWW: http://80386.nl/
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