make -j3?

perfect_circle · 03-03-2005, 03:14 AM

in some slackbuild scripts like xine's I've seen "make -j3". Does anybody know what this -j3 is?
THANX

KMcD · 03-03-2005, 03:52 AM

(I'm not all up on compiler lingo but I'll give this a go)

the "-j" flag tells the compiler how many threads to build at once. So if you have -j3 it tries to build 3 files at once.

This is handy if you use a distributed compiler, like distcc.

perfect_circle · 03-03-2005, 04:24 AM

Quote:

Originally posted by KMcD
(I'm not all up on compiler lingo but I'll give this a go)

the "-j" flag tells the compiler how many threads to build at once. So if you have -j3 it tries to build 3 files at once.

This is handy if you use a distributed compiler, like distcc.

So this has affect only on compilation time?
Building 3 threads in a single cpu machine, will only reduce a little bit the compilation time, since the cpu won't have to wait a lot for I/O, it can start the next thread, if the first is waiting for I/O. Am I correct?
I cannot think of something else...

KMcD · 03-03-2005, 05:22 AM

Yep, as per my understanding you are correct.