Re: WIP: bufmgr rewrite per recent discussions

Tom Lane wrote:
> I don't feel this is quite ready to commit, but here it is if anyone
> would like to try some performance testing.  Using "pgbench -s 10"
> on a single-CPU machine, I find this code a little slower than CVS tip
> at shared_buffers = 1000, but noticeably faster (~10% speedup) at
> 10000 buffers.  So it's not a dead loss for single-CPU anyway.  What
> we need now is some performance measurements on multi-CPU boxes.
>
> The bgwriter algorithm probably needs more work, maybe some more GUC
> parameters.
>

Here are some results for a 2xPIII 700Mhz with 2G ram running Freebsd 5.3:

Pgbench:  s=10 c=4 t=1000
Pg:       wal_buffers=128 checkpoint_segments=10
           shared_buffers=1000|10000

3 runs of each combination were averaged. the figure is the tps
including connection time (with range in the brackets).


8.1 CVS

shared_buffers=1000   tps=129 (129-131)
shared_buffers=10000  tps=146 (145-148)

8.1 CVS + buf patch

shared_buffers=1000   tps=135 (131-138)
shared_buffers=10000  tps=154 (154-155)

regards

Mark