[SOLVED] How do I build a pkg using more than one cpu core?

irgunII · 03-07-2014, 09:18 AM

I found this answer once, a good while ago, but for the life of me can't find it now.

Someone told me or another poster where to put something like '-j<# of cores to use>' so that any time I built a package from slackbuilds.org, it would use the number of cores I specified every time so that I didn't have to constantly keep inserting it into the <package>.SlackBuild script.

ReaperX7 · 03-07-2014, 09:20 AM

make -j2

Note that some packages can't build with parallel building.

moisespedro · 03-07-2014, 09:25 AM

I think you can set the make variable on /etc/profile. Or maybe use a bash alias?
alias make='make -j4' (for example)

szboardstretcher · 03-07-2014, 09:36 AM

Quote:

Originally Posted by ReaperX7

Note that some packages can't build with parallel building.

This is the most important thing to remember.

Richard Cranium · 03-07-2014, 10:26 AM

The MAKEFLAGS environmental variable is honored by make:

Code:

export MAKEFLAGS=' -j10'

But as others have pointed out, some packages cannot be built in parallel. clisp comes to mind.

dederon · 03-07-2014, 10:43 AM

Quote:

Originally Posted by Richard Cranium

The MAKEFLAGS environmental variable is honored by make:

Code:

export MAKEFLAGS=' -j10'

But as others have pointed out, some packages cannot be built in parallel. clisp comes to mind.

thats the way to go. this won't break any slackbuild - the slackbuilds which need non parallel build use "make -j1".

@moisespedro: alias make='make -j4'? are you serious?

genss · 03-07-2014, 10:55 AM

Quote:

Originally Posted by Richard Cranium

The MAKEFLAGS environmental variable is honored by make:

Code:

export MAKEFLAGS=' -j10'

i never put the space before -j
is that for a good habit ?

granth · 03-07-2014, 11:09 AM

Here's a way to determine your CPU count and adjust accordingly.

Code:

CORES=`nproc`
JOBS=`expr $CORES + 1`
export MAKEFLAGS="-j${JOBS}"

I've come across one Slackbuild that doesn't work with this, so I override it in the sqf.

Code:

$ cat avr-libc.sqf
@avr-gcc
avr-libc | MAKEFLAGS='-j1'

moisespedro · 03-07-2014, 11:30 AM

Quote:

Originally Posted by dederon

thats the way to go. this won't break any slackbuild - the slackbuilds which need non parallel build use "make -j1".

@moisespedro: alias make='make -j4'? are you serious?

What?

irgunII · 03-07-2014, 07:50 PM

Quote:

Originally Posted by dederon

thats the way to go. this won't break any slackbuild - the slackbuilds which need non parallel build use "make -j1".

So you mean then that if I forget to use -j1 during a build of foo.SlackBuild, and it's one of those builds that can't use the '-jX', it *won't* break and will automatically us -j1?

Richard Cranium · 03-07-2014, 08:20 PM

Quote:

Originally Posted by genss

i never put the space before -j
is that for a good habit ?

It helps when someone puts...

Code:

MAKEFLAGS=-m64${MAKEFLAGS}

...but I should probably put a space after the -j4 too.

dederon · 03-08-2014, 01:40 AM

Quote:

Originally Posted by irgunII

So you mean then that if I forget to use -j1 during a build of foo.SlackBuild, and it's one of those builds that can't use the '-jX', it *won't* break and will automatically us -j1?

slackbuilds are ordenary shell scripts, just look into the code. if the build process requires a sequencial build you will find a "make -j1" line in the slackbuild. this will overwrite MAKEFLAGS. example: webkitgtk.

if not, complain to the maintainer. or even better: provide a git patch.

Drakeo · 03-08-2014, 07:17 AM

if you take a look at Pat's build scripts for Slackware you will see how he does it. looks to me like he been asking it to do -j7 for a long time.

-j2,3,4, etc etc doesn't really mean cores because it means how it stacks up the build instructions to the cores.

many programs that built fast and clean I can do a -j12 on my 8 core . and for years doing a make -j one over the amount of cores you have
has been used for a long time to make sure all cores are at 100 percent through the build.

if you have a 8 core machine and your setting up to run -j4 that will push the stack to 4 at a time.

since I like to play games and do stuff during long and large compiling jobs. I will set mine to -j6 so as to keep resources for other process
with out grinding to a halt.

irgunII · 03-08-2014, 01:24 PM

Thanks everyone. Got the answers I needed and all were a great help and very informational.

Martinus2u · 03-09-2014, 04:26 AM

Quote:

Originally Posted by granth

Here's a way to determine your CPU count and adjust accordingly.

...

on a side note, with a decent CPU scheduler like BFS it is totally sufficient to say

Code:

CORES=`nproc`
export MAKEFLAGS="-j${CORES}"