Subject: Re: Thread benchmarks, round 2
To: Kris Kennaway <>
From: Kris Kennaway <>
List: tech-kern
Date: 10/06/2007 18:20:58
Kris Kennaway wrote:

> In the meantime I ran sysbench with postgresql 8.2.  Same NetBSD configs 
> as before (except I built my own kernel with the sched_m2 patches since 
> I needed to tweak the sysv ipc parameters).
> postgresql is much more scalable than mysql on this workload and doesn't 
> have silly scaling bottlenecks inside the application (cf the tail of 
> the FreeBSD curve for mysql which is where pthread mutex contention 
> kicked in).

Here are some more graphs.

This one is on the 4 CPU P3 500 MHz and shows postgresql 8.2.  FreeBSD 
is about 15-20% higher throughput.

This one shows mysql on the same system

In that test NetBSD does outperform FreeBSD but only by 3-4% (in 
particular I am not seeing the ~10% difference that Andrew observes on 
his 4*p3 700MHz).  Given the age of the hardware and the fact that I am 
not seeing it on other workloads or on modern hardware it might just be 
due to a small scheduling difference on this configuration.