Re: Perfomance degradation 9.3 (vs 9.2) for FreeBSD

> 20 apr 2014 kl. 12:19 skrev Francois Tigeot <ftigeot(at)wolfpond(dot)org>:
>
> Hi,
>
>> On Sun, Apr 20, 2014 at 11:24:38AM +0200, Palle Girgensohn wrote:
>>
>> I see performance degradation with PostgreSQL 9.3 vs 9.2 on FreeBSD, and I'm wondering who to poke to mitigate the problem. In reference to this thread [1], who where the FreeBSD people that Francois mentioned?
>
> At least one FreeBSD hacker came to discuss it on the #dragonflybsd irc
> channel and tried to run the benchmark on a 80-core machine.
>
> I didn't keep logs and don't remember his/their name(s) but there was
> definitely some FreeBSD effort at the time to investigate and fix things.
>
>> If mmap needs to perform well in the kernel, I'd like to know of someone with FreeBSD kernel knowledge who is interested in working with mmap perfocmance. If mmap is indeed the cuplrit, I've just tested 9.2.8 vs 9.3.4, I nevere isolated the mmap patch, although I believe Francois did just that with similar results.
>
> I did test the 9.3 -devel branch before and after the SysV shared memory =>
> mmap commit. The performance degradation was visible.
>
> I recently ran a few benchmarks of PostgreSQL 9.3 with different operating systems
> including DragonFly 3.6 and FreeBSD 10. You may be interested in the results:
>
> http://lists.dragonflybsd.org/pipermail/users/2014-March/128216.html
>

Interesting, indeed. The fixes to dragonfly where made quite recently, in 3.2, right? Was it an isolated patch that could perhaps be used as inspiration for a similar fix on freebsd, or is it the major rewrite of the scheduler mentioned in [http://m.slashdot.org/story/177299]?

Palle

> --
> Francois Tigeot