make -j doesn't work on Slack64 14.1

Linux.tar.gz · 04-27-2014, 03:34 AM

Hi,

I'm on a Core i3 laptop.

I installed a bunch of SBo packages, and i'm now compiling a kernel.
I have 4 visible processors, but make -j8 still use only one at a time or 25% of each.

I don't know where to start to debug.

pan64 · 04-27-2014, 05:15 AM

you can try to check it with htop for example. You should see several build commands running parallel. You also can try to use -j16 or -j1 to see if there were any differences.

Richard Cranium · 04-27-2014, 12:34 PM

What does "echo $MAKEFLAGS" output?

Linux.tar.gz · 04-28-2014, 12:27 PM

It outputs blank.

Tried to change it, nothing.
Also tried to increase the -j, nothing.

Linux.tar.gz · 04-28-2014, 12:45 PM

WTF !!! I realized i have the same problem on another machine !

I was able to compile a kernel yesterday with 4 cpu, today i can't (i'm using the same host kernel).

Richard Cranium · 04-28-2014, 04:46 PM

Quote:

Originally Posted by Linux.tar.gz

It outputs blank.

OK, it's not overriding what you are attempting to use, so that's good.

Quote:

Tried to change it, nothing.

What does that mean?

[/QUOTE]Also tried to increase the -j, nothing.[/QUOTE]

Well, here's a quick test: Grab the source for clisp and apply the patche that I mention here.

You'll want to not force "make -j1 blah" that I have in the last code block of the post. You can keep it at "-j7" or whatever.

If you run that slackbuild and it fails, then you can be pretty sure that you are running multiple compile jobs.

pan64 · 04-30-2014, 10:38 AM

Just please tell me how do you know "make -j8 still use only one at a time"? Have you tried htop or top or something similar?

Linux.tar.gz · 05-01-2014, 02:45 AM

I look at both gkrellm and top.