Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 19 Dec 2000 09:38:58 -0800
From:      Alfred Perlstein <bright@wintelcom.net>
To:        Alessandro de Manzano <demanzano@iol.it>
Cc:        stable@freebsd.org
Subject:   Re: make -j
Message-ID:  <20001219093858.N19572@fw.wintelcom.net>
In-Reply-To: <20001219122433.A1961@libero.sunshine.ale>; from demanzano@iol.it on Tue, Dec 19, 2000 at 12:24:34PM %2B0100
References:  <Pine.LNX.4.10.10012181816270.29890-100000@inet.ssc.nsu.ru> <20001218101613.Y19572@fw.wintelcom.net> <20001219122433.A1961@libero.sunshine.ale>

next in thread | previous in thread | raw e-mail | index | archive | help
* Alessandro de Manzano <demanzano@iol.it> [001219 03:25] wrote:
> > The rule with -j is that it _should_ work, if it doesn't then try
> > without -j and let us know.
> 
> I did a buildworld/buildkernel last week with "-j 8" on my dual celeron system and all, apparently, went fine.
> It saved about 30-40% of time. Version 4.2-stable.
> 
> Could someone, please, explain to me why the "-j" stuff could be dangerous ?
> It's not much clear to me why doing more then one "cc" (example) at time could break the final object code.
> (no flame, it's a very honest question! :-) )

It's possible for incorrectly set up dependancies to cause files to
be compiled incorrectly.  It's also possible that incorrectly set up
dependancies can cause the build to fail.

> > 4-8 is good for a single processor with enough ram (gcc is large),
> > 4-24 is ok for a SMP box.
> 
> I did with 8 and now trying with 10 (I've only 96Mb RAM)

That may be a bit much, if you start swapping because of it
that's one way to know you're using too high of a -j.

-- 
-Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org]
"I have the heart of a child; I keep it in a jar on my desk."


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20001219093858.N19572>