Re: SMP Read-only Performance

Greg Smith <greg <at> 2ndquadrant.com> writes:
> You're probably running into this problem:
> http://notemagnet.blogspot.com/2008/05/pgbench-suffering-with-linux-2623-2626.html

You are so right. The last thing I would have suspected is a kernel bug. I am
definitely going to try to be more aware of kernel happenings from now on. Thank
you!

-bash-3.2$ uname -a
Linux devpgre 2.6.25-14.fc9.x86_64 #1 SMP Thu May 1 06:06:21 EDT 2008 x86_64
x86_64 x86_64 GNU/Linux

-bash-3.2$ pgbench -c 1 -S -t 400000 -h localhost test
starting vacuum...end.
transaction type: SELECT only
scaling factor: 64
number of clients: 1
number of transactions per client: 400000
number of transactions actually processed: 400000/400000
tps = 10716.907529 (including connections establishing)
tps = 10717.650674 (excluding connections establishing)

-bash-3.2$ pgbench -c 2 -S -t 400000 -h localhost test
starting vacuum...end.
transaction type: SELECT only
scaling factor: 64
number of clients: 2
number of transactions per client: 400000
number of transactions actually processed: 800000/800000
tps = 14355.737471 (including connections establishing)
tps = 14356.991106 (excluding connections establishing)

-bash-3.2$ pgbench -c 3 -S -t 400000 -h localhost test
starting vacuum...end.
transaction type: SELECT only
scaling factor: 64
number of clients: 3
number of transactions per client: 400000
number of transactions actually processed: 1200000/1200000
tps = 19068.715403 (including connections establishing)
tps = 19070.958268 (excluding connections establishing)

-bash-3.2$ pgbench -c 4 -S -t 400000 -h localhost test
starting vacuum...end.
transaction type: SELECT only
scaling factor: 64
number of clients: 4
number of transactions per client: 400000
number of transactions actually processed: 1600000/1600000
tps = 22951.995256 (including connections establishing)
tps = 22955.104092 (excluding connections establishing)