Re: Hugetables question

Martijn van Oosterhout <kleptog(at)svana(dot)org> Thursday 23 of June 2011 09:10:20
> On Wed, Jun 22, 2011 at 02:31:01PM +0200, Rados??aw Smogura wrote:
> > I strictly disagree with opinion if there is 1% it's worthless. 1%
> > here, 1% there, and finally You get 10%, but of course hugepages
> > will work quite well if will be used in code that require many
> > random "jumps". I think this can be reproduced and some not-common
> > case may be found to get performance of about 10% (maybe upload
> > whole table in shared buffer and randomly "peek" records one by
> > one).
>
> I think the point is not that 1% is worthless, but that it hasn't been
> shown that it is a 1% improvement, becuase the noise is too large.
>
> For benefits this small, what you need to is run each test 100 times
> and check the mean and standard deviation and see whether the
> improvment is real or not.
>
> When the benefit is 10% you only need a handful of runs to prove it,
> which is why they're accepted easier.
>
> Have a nice day,
>
> > Patriotism is when love of your own people comes first; nationalism,
> > when hate for people other than your own comes first.
> >
> > - Charles de Gaulle
I think conclusion from this test was "Much more important things are to do,
then 1% benefit" - not "1% is worthless".

I will try today hugepages, with random peeks.

Regards,
Radek