OpenMosix and CFLAGS

nuance9 · Tux's lil' helper Joined: 09 Sep 2002 Posts: 85

I have seen various posts on the topic and am wondering if there is a current answer.

I am currently installing Gentoo 1.4_rc2 on a slow P150 laptop - so, needless to say, it is taking a while.

I started the process with the following CFLAGs:

"-march= pentium -O3 -pipe -fomit-frame-pointer"

While it has been installing I have been looking over the forums and have become intrigued with the idea of setting this computer and my others up as an OpenMosix cluster.

But my question is this, will the current install of Gentoo and OpenMosix work with these CFLAGs or do I need to change them to -O2?

If I do, do I just emerge -e world or what to change the CFLAGS?

Thanks!

- JP

AlterEgo · Veteran Joined: 25 Apr 2002 Posts: 1619

For installing Gentoo, openmosix is not very effective:
distcc (search the forum) is much more efficient than openmosix for compiling . For running applications in userspace, openmosix is awsome

Some facts: emerge kdeadmin (2 more or less identical machines):
1 machine: 42 minutes
openmosix (2 machines): 38 minutes
distcc (2 machines): 25 (!) minutes

To anwer your question: openmosix moves threads from one CPU to another;
this means that an order to compile <whatever> is sent (briefly) to another PC. It will take all flags/options etc along, as long as possible: you'd probably run into trouble if you join a machine running gcc 2.95/glibc 2.2 with one using gcc 3.2/glkibc 2.3.
Therefore, you can you different Cflags on both PC's, Just be sure to use the same kernel version and openmosix patch on both machine.
I run openmosix using CFLAGS="-march=athlon-xp -mmmx -m3dnow -msse -mfpmath=sse -O3 -pipe -fomit-frame-pointer -funroll-loops -fforce-addr -frerun-cse-after-loop -frerun-loop-opt -falign-functions=4" on one box and CFLAGS=athlon -O3 -pipe on the other.

UnderDog138 · Posted: Thu Jan 09, 2003 11:36 am Post subject:

I'm using distcc to compile gentoo on my old p166 64mb ram. It's quite nice once you get it working right. It's piggy-backing on my athlon xp 1.533 512mb.

This is the thread I read to get it working. I used the procedure on the second post, not the first, as the first looked quite messy.

https://forums.gentoo.org/viewtopic.php?t=16455&highlight=distcc
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