RE: [gentoo-user] Re: May be OT: recommended niceness settings for Portage while using Gnome?

[James Homuth]

-----Original Message-----
From: news [mailto:news@×××××××××.org] On Behalf Of Nikos Chantziaras
Sent: August 21, 2009 1:50 PM
To: gentoo-user@l.g.o
Subject: [gentoo-user] Re: May be OT: recommended niceness settings for
Portage while using Gnome?

On 08/21/2009 07:54 PM, James Homuth wrote:
>
> I just got Gnome set up completely on a 5-year-old laptop with 512 MB
> of RAM running on a P4, and am sort of halfway in the middle of
> playing with it. In the process, I'm discovering I still need to
> install a few things. Just one problem. I emerge said things, and the
> system flatlines until such time as the compilation(s) are done--load
> is currently sitting at 2.1+. Are there any make.conf settings I can
> tweak so that I can still actually use the system while things
> compile, or would I be better off setting things to compile, throwing
> in a movie, and coming back when they're done? Thanks for any pointers.

Not sure if something changed in recent kernels, but 19 used to be the most
efficient value since processes running at 19 are considered batch jobs.
They get plenty of CPU time due to longer time-slices (responsiveness
suffers, but you don't care about portage being responsive in the first
place, so it's optimal.)  So:

   PORTAGE_NICENESS=19

Is best.  However, also very important is "I/O nice".  Setting an ionice
value of "idle" will result in portage not blocking your other applications
whey they need to do disk I/O:

   PORTAGE_IONICE_COMMAND="ionice -c 3 -p \${PID}"

This needs a kernel newer than 2.6.16 and it has to be configured to use the
CFQ scheduler.  You know if that's the case if this command:

   zgrep CFQ /proc/config.gz

says:

   CONFIG_IOSCHED_CFQ=y
   CONFIG_DEFAULT_CFQ=y


It does not. I was thinking about upgrading to 2.6.30 anyway, so which
switch would I throw to enable it?