On Saturday 27 December 2008 21:13:49 Nikos Chantziaras wrote:
> Dale wrote:
> > Nikos Chantziaras wrote:
> >> On my Gentoo at home, yes. The mouse cursor skips, scrolling gets
> >> skippy/laggy too. I have a dual core e6...@3.33ghz with 4GB DDR2 RAM.
> >
> > I have to use version 2.6.23-gentoo-r8 for my kernel or it does the same
> > thing. Someone mentioned that it is a setting in the kernel for one of
> > the new features. At some point I plan to post the info here and try to
> > figure out what setting I should use but just haven't done it yet.
> >
> > The only other thing I can think of is the drives being busy. I think
> > they have ionice now too.
>
> I have this in my make.conf:
>
> PORTAGE_IONICE_COMMAND="ionice -c 3 -p \${PID}"
>
> Helped a bit. But still the GUI (KDE 3.5.10) gets pretty laggy. Just a
> few hours ago I updated to gcc-4.3.2-r1. Even with nice 19 and ionice
> 3, lag is there.
>
> I hope someone finds the magic button in the kernel config to fix that :P
There isn't one - at least not one that really works.
Linux mostly ignores NICE and has done so since day one. The reason according
to Linux himself on some LKML post quite a while back is that Linux has a
semi-decent task scheduler and nice is a 100% manual task scheduler.
Therefore nice is not needed. It did have some uses, such as respecting nice
settings for having X if set to something very negative - makes gui apps more
responsive (X tends to use little cpu and IO time overall but users want it
to be responsive). This has largely gone away with Ingo's last task
scheduler.
On other Unixes, nice has normally been nothing more than a gentle hint to the
kernel how the admin would like the systems to treat a certain process.
That's why Linux could ignore it and get away with it.
You will likely always experience lag compiling something like gcc. It uses
gcc to build a new one, and gcc grabs enormous amounts of memory to do this.
Plus it's rather disk intensive as well. So, running gcc on a large build is
likely to produce lags anyway due to swap and IO no matter how you nice it.
More so if resources are constrained.
--
alan dot mckinnon at gmail dot com
