Re: 20% performance drop on PostgreSQL 9.2 from kernel 3.5.3 to 3.6-rc5 on AMD chipsets - bisected

Borislav Petkov
2012-09-27T16:25:14Z

On Thu, Sep 27, 2012 at 09:10:11AM +0200, Ingo Molnar wrote:
> The theory would be that this patch fixes psql performance, with CPU
> selection being a measurable but second order of magnitude effect. How
> well does practice match theory in this case?

Yeah, it looks a bit better than default linux. A whopping 9% perf delta
:-).

v3.6-rc7-1897-g28381f207bd7 (linus from 26/9 + tip/auto-latest) + performance governor
======================================================================================

plain
-----
tps = 4574.570857 (including connections establishing)
tps = 4579.166159 (excluding connections establishing)

kill select_idle_sibling
------------------------
tps = 2230.354093 (including connections establishing)
tps = 2231.412169 (excluding connections establishing)

NO_WAKEUP_PREEMPTION
--------------------
tps = 4991.206742 (including connections establishing)
tps = 4996.743622 (excluding connections establishing)

--
Regards/Gruss,
Boris.