On Wed, May 30, 2012 at 10:38:10AM -0700, Jeff Janes wrote: > On Wed, May 30, 2012 at 9:56 AM, Bruce Momjian <br...@momjian.us> wrote: > > As part of a blog, I started looking at how a user could measure the > > pressure on shared buffers, e.g. how much are they being used, recycled, > > etc. > > > > They way you normally do it on older operating systems is to see how > > many buffers on the free list (about to be reused) are reclaimed as > > needed --- that usually indicates kernel cache pressure. Unfortunately, > > we don't have a freelist, except for initial assignment of shared > > buffers on startup. > > Isn't that what the buffers_alloc from pg_stat_bgwriter is ?
The issue is that once a buffer is removed from the free list, it is never returned to the free list. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
