Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 27 May 1996 12:31:42 -0400 (EDT)
From:      "matthew c. mead" <mmead@Glock.COM>
To:        joerg_wunsch@uriah.heep.sax.de
Cc:        freebsd-hackers@freebsd.org
Subject:   Re: CHILD_MAX
Message-ID:  <199605271631.MAA05895@Glock.COM>
In-Reply-To: <199605271603.SAA00854@uriah.heep.sax.de> from "J Wunsch" at May 27, 96 06:03:30 pm

next in thread | previous in thread | raw e-mail | index | archive | help
J Wunsch writes:

> As matthew c. mead wrote:
> >     Does anyone know why CHILD_MAX for the kernel and CHILD_MAX
> > in the /usr/include/sys/syslimits.h are different (128 and 40
> > respectively)?  I'm running into the problem of having too few
> > processes available.  If I redefine the define in syslimits.h to
> > 128 will I be able to run right away, or am I correct in
> > presuming that I'm going to have to rebuild things?  What all
> > will I have to rebuild?

> The correct way is

> 	options		"CHILD_MAX=128"

> and rebuild the kernel.

	I thought I'd seen someone say that this didn't work.
Are you sure that CHILD_MAX=128 in the kernel is not the default?
Does syslimits.h really not need to be changed from 40?

> I've once got the idea to make this limit dynamic, depending on the
> size of the machine (amount of physical memory, speed of CPU), since
> it's mostly there to prevent denial of resource attacks (like the
> ``fork trap'').  The current static limit doesn't fullfill this, it's
> too high for a 386/16 w/ 4 MB RAM, and far too low for wcarchive.

> Nobody (including me) ever got round to implement this however.

	Hmm.  How difficult an undertaking is it?



-matt

-- 
Matthew C. Mead

mmead@Glock.COM
http://www.goof.com/~mmead/



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199605271631.MAA05895>