How to increase maximum user cpu usage allowed on a multi core system?
stan
stanl-fedorauser at vfemail.net
Tue Mar 17 15:48:57 UTC 2015
On Mon, 16 Mar 2015 16:05:37 +0100
Heinz Diehl <htd+ml at fritha.org> wrote:
> On 09.03.2015, Martin Cigorraga wrote:
>
> > Just a minor clarification: when compiling, the -j flag should
> > point to a unit above your available cores in order to fully
> > utilize all of them.
>
> Curious what would happen, I remembered this mail when compiling a
> new kernel today. A "nice -n 19 make -j" opened *hundreds* of cc
> incarnations, pushed the load to over 800 and seriously blocked the
> machine (an 8-core Xeon with 16 GB of RAM) within *seconds*!
Lucky you!
Are you using F21? Which kernel?
So, are you using rpmbuild with the src.rpm package, or compiling
directly from the source tree?
What happens if you use -j 4? I would think you should get somewhere
between 3 and 4 cores. The recommendation I saw to fully use all
cores, were from cores+1 to cores*3. Cores*1.5 was a popular one, to
allow for io slowness.
When I tried -j, I saw all the jobs queue, but only one core was used.
Thanks for reporting back.
More information about the users
mailing list