Hi, On Mon, 4 Jun 2012, Ants Aasma wrote:
On Mon, Jun 4, 2012 at 7:44 PM, Merlin Moncure <mmonc...@gmail.com> wrote: I tried to keep it simple at first to find an answer to the question if it's even worth trying before expending large effort on it. If anyone with a multisocket machine would chip in, I'd love to know how this patch handles on larger machines. I think the most interesting workloads are read only loads with heavy buffer trashing but inside OS memory. Select only pgbench with 32MB shared_buffers was withÃn error margin, although slightly faster on my machine (Intel i2500K). The workload that I used to demonstrate gain was an aggregated index scan to minimise other overheads.
I've quickly tested your lockfree-getbuffer.patch patch with the test case you provided and I barely see any improvement (2% at max)
https://docs.google.com/open?id=0B7koR68V2nM1QVBxWGpZdW4wd0U tested with 24 core (48 ht cores, Xeon E7- 4807). Although the tps vs number of threads looks weird.... Cheers, S ***************************************************** Sergey E. Koposov, PhD, Research Associate Institute of Astronomy, University of Cambridge Madingley road, CB3 0HA, Cambridge, UK Tel: +44-1223-337-551 Web: http://www.ast.cam.ac.uk/~koposov/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
