On Wednesday, November 21, 2012 4:21 AM Jeff Janes wrote: > On Tue, Nov 20, 2012 at 1:26 PM, Merlin Moncure <mmonc...@gmail.com> > wrote: > > In this sprawling thread on scaling issues [1], the topic meandered > > into StrategyGetBuffer() -- in particular the clock sweep loop. I'm > > wondering: > >
> > > > *) Since the purpose of usage_count is to act on advisory basis to > > keep recently/frequently accessed buffers from being discarded, is it > > really necessary to rigorously guard the count with a spinlock? If a > > ++ or -- operation on the value gets missed here or there, how big of > > a deal is it really? > > I don't think it is all that big of a deal. > > I've implemented this patch to do that. It still applies to head. > > http://archives.postgresql.org/pgsql-hackers/2011-08/msg00305.php > > It was very effective at removing BufFreelistLock contention on the > system I had at the time. In that case, why don't we work towards reducing it? Is the generic use case a problem or will it effect any generic scenario in negative way? With Regards, Amit Kapila. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
