Re: Perfomance degradation 9.3 (vs 9.2) for FreeBSD

On 4/21/14 4:10 AM, Andres Freund wrote:
> Hi,
>
> On 2014-04-20 11:24:38 +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? 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.
> If there are indeed such large regressions on FreeBSD we need to treat
> them as postgres regressions. It's nicer not to add config options for
> things that don't need it, but apparently that's not the case here.
>
> Imo this means we need to add GUC to control wether anon mmap() or sysv
> shmem is to be used. In 9.3.
>
> Greetings,
>
> Andres Freund
>
Andres, thank you. Speaking as a FreeBSD developer that would be a good
idea.

-Alfred