Re: bad interactive performance when building

[Antti Kantee <pooka%cs.hut.fi@localhost>]

On Wed Feb 25 2009 at 19:42:57 +0100, Adam Hoka wrote:
> Antti Kantee wrote:
> 
> > Has anyone noticed that the UI slows down considerably on 5.0 when
> > building with a high enough -j and doing something which consumes a
> > little CPU for UI processes (e.g. minimize/maximize a web browser).
> > This happens both with 4BSD and M2.  I never saw it on 4.99.42.
> > 
> > I realize this may be simply because 5.0 is faster, but I don't know if
> > we can call it progress if a faster system feels slower to the user.
> 
> Yeah I see this effect too. Running Xorg with nice -10 or even real time
> priority usually makes a huge difference under load...

That is obvious.  However, the question is why it wasn't necessary
previously and how do we fix the default again so that users who do not
necessarily know they need to run X with a negative nice (or builds with
a positive one) continue to get good interactive performance.

The cheap solution would be to fix the installer to nice X and the
window manager to a negative value, although that may have some root
priv implications.

Offline someone suggested tweaking the scheduler constants for punishing
pig processes.