Messages in this thread | | | Date | Sat, 15 Sep 2012 22:32:12 +0100 | From | Alan Cox <> | Subject | Re: 20% performance drop on PostgreSQL 9.2 from kernel 3.5.3 to 3.6-rc5 on AMD chipsets - bisected |
| |
> Yes, postgress performs loads better with it's spinlocks, but due to > that, it necessarily _hates_ preemption. How the is the scheduler > supposed to know that any specific userland task _really_ shouldn't be > preempted at any specific time, else bad things follow?
You provide a shared page for a process group so it can write hints to which is kernel mapped so the scheduler can peek..
Alan
| |