Re: pgbench cpu overhead (was Re: lazy vxid locks, v1)

On 06/14/2011 02:27 AM, Jeff Janes wrote:
> On Mon, Jun 13, 2011 at 7:03 AM, Stefan Kaltenbrunner
> <stefan(at)kaltenbrunner(dot)cc> wrote:
> ...
>>
>>
>> so it seems that sysbench is actually significantly less overhead than
>> pgbench and the lower throughput at the higher conncurency seems to be
>> cause by sysbench being able to stress the backend even more than
>> pgbench can.
>
> Hi Stefan,
>
> pgbench sends each query (per connection) and waits for the reply
> before sending another.
>
> Do we know whether sysbench does that, or if it just stuffs the
> kernel's IPC buffer full of queries without synchronously waiting for
> individual replies?
>
> I can't get sysbench to "make" for me, or I'd strace in single client
> mode and see what kind of messages are going back and forth.

yeah sysbench compiled from a release tarball needs some
autoconf/makefile hackery to get running on a modern system - but I can
provide you with the data you are interested in if you tell me exactly
what you are looking for...

Stefan