On 2014-10-03 11:51:46 -0400, Robert Haas wrote:
> On Fri, Oct 3, 2014 at 11:33 AM, Bruce Momjian <bruce@momjian.us> wrote:
> > I am assuming almost no one cares about the number of locks, but rather
> > they care about cummulative lock durations.
> >
> > I am having trouble seeing any other option that has such a good
> > cost/benefit profile.
>
> I do think that the instrumentation data gathered by LWLOCK_STATS is
> useful - very useful.
>
> But it does have significant overhead.
Have you ever analyzed where that overhead is with the current code?
I do wonder if having a per backend array in shmem indexed by the lockid
(inside its tranche) wouldn't be quite doable for the smaller tranches.
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services
