ULE vs. 4BSD scheduler benchmarks

Ivan Voras ivoras at freebsd.org
Mon Jan 30 14:01:36 UTC 2012

On 28/01/2012 23:40, Florian Smeets wrote:

> The conclusion right now seems to be that ULE is faster for database
> workload,

I've done the same benchmarks with Bullet Cache last year and 4BSD is 
*ridiculously* inefficient and slow for this specific workload which 
involves a lot of inter-thread and inter-process communications. The 
results were somewhere in the ratio of 1:10 in favor of ULE.

>but for strongly CPU-bound workloads 4BSD can be a better
> choice. I can provide KTR traces and/or schedgraph output for cases
> where 4BSD is better than ULE.

Can you try manually bind processes to CPUs with the CPU-heavy 
benchmark? This could be a bit hard if you use the regular pbzip2 
because it spawns threads, but if you manually spawn 8 CPU-bound 
processes (with cpuset(1)) in parallel and measure that, it would be useful.

More information about the freebsd-performance mailing list