Messages in this thread | | | Subject | Re: Poor PostgreSQL scaling on Linux 2.6.25-rc5 (vs 2.6.22) | From | Nicholas Miell <> | Date | Tue, 11 Mar 2008 16:12:12 -0700 |
| |
On Tue, 2008-03-11 at 22:34 +0100, Cyrus Massoumi wrote: > Nicholas Miell wrote: > > > (Also, ignoring MySQL because it's a terrible piece of software at least > > when regarding it's scalability is a bad idea. It's the M in LAMP, it > > has a huge user base, and FreeBSD manages to outperform Linux with the > > same unscalable piece of software.) > > Did you actually see this? > http://www.kernel.org/pub/linux/kernel/people/npiggin/sysbench/ > > FreeBSD does not outperform Linux, it's actually a bit faster according > to Nick's tests.
I am aware of those results, but in the mail I was responding to, Nick Piggin said the following:
> The problem with MySQL contention means that if the scheduler > unluckily chooses to deschedule a lock holder, then you can get > idle time building up on other cores and you can get context switch > cascades as things all pile up onto this heavily contended lock. As > such, it means MySQL is not an ideal candidate for looking at > performance behaviour. I discounted the relatively worse scaling of > MySQL with 2.6.25-rc (than 2.6.22) as such an effect.
which I interpreted to mean that MySQL performs worse on 2.6.23+ than on 2.6.22 but for some reason this doesn't matter.
-- Nicholas Miell <nmiell@comcast.net>
| |