On 2014-12-23 22:51:22 -0500, Bruce Momjian wrote: > Many of these are 64-byte aligned, including Buffer Descriptors.
In that case you need to change max_connections, some settings will lead to unaligned BufferDescriptors. > I > tested pgbench with these commands: > > $ pgbench -i -s 95 pgbench > $ pgbench -S -c 95 -j 95 -t 100000 pgbench > > on a 16-core Xeon server and got 84k tps. I then applied another patch, > attached, which causes all the structures to be non-64-byte aligned, but > got the same tps number. 'Xeon' itself doesn't say much. It's been applied to widly different CPUs over the years. I guess that was a single socket server? You're much more likely to see significant problems on a multi node NUMA servers where the penalties for cache misses/false sharing are a magnitude or three higher. > Can someone test these patches on an AMD CPU and see if you see a > difference? Thanks. I don't think you'll see a bigger difference there. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
