Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 03 May 2001 13:01:19 -0700
From:      John Merryweather Cooper <jmcoopr@webmail.bmi.net>
To:        David Wolfskill <dhw@whistle.com>
Cc:        FreeBSD-STABLE Mailing List <freebsd-stable@FreeBSD.ORG>
Subject:   Re: Should /sys/i386/conf/GENERIC's SysV shared memory settings defaults  be re-thought?
Message-ID:  <3AF1B90F.30DA4861@webmail.bmi.net>
References:  <200105031913.f43JDjw72049@pau-amma.whistle.com>

next in thread | previous in thread | raw e-mail | index | archive | help
David Wolfskill wrote:
> 
> >Date: Thu, 03 May 2001 12:01:40 -0700
> >From: John Merryweather Cooper <jmcoopr@webmail.bmi.net>
> 
> >After finally getting Amanda up and running on my system, I noticed that
> >my cron jobs for amdump would crash with an error in SHMGET if X was
> >running when the amdump job was scheduled.  I have also been plagued by
> >IMLIB SHM memory allocation errors.  I have just discovered that, by
> >increasing the defaults for all the SysV settings listed in LINT, I have
> >been able to make all those errors disappear; and Amanda will now run to
> >completion even with X running.  I increased all these settings by about
> >a factor of x8--remembering that in OS/2 half of all physical memory was
> >made available for shared memory operations--giving me 32 megs of shared
> >memory.
> 
> Hmmm....
> 
> >...
> 
> >Thoughts?
> 
> I find this somewhat surprising, since I've been backing up not only the
> servers here, but also the important desktops (the ones running FreeBSD)
> on engineers' desks here for around 2.5 years using amanda.  And the
> engineers generally run X... but I've never encountered that problem.
> (Before the shared memory stuff was included in GENERIC, I included it
> manually in the kernels when I set up their machines.  I just left the
> default settings alone.)
> 
Even with just GNOME+Enlightenment running, stderr is full of IMLIB
error messages unless I alter the SysV parameters.  Xsreensaver also
triggers what look like shared memory errors with some of the modules. 
Netscape (a known memory-hog in any configuration) also generates these
errors.  They generally aren't fatal (everything seems to work o.k.),
but I'm glad they're gone now . . .

> I suppose it may depend on the particular X workload; for example, I use
> tvtwm as a window manager, while I understand that some folks prefer the
> appearance or behavior of a window manager that is a bit more resource-
> intensive.

I'm using GNOME+Enlightenment with a smattering of KDE tools (I like
KNode) . . . 

> I do tend to kick "maxusers" up a bit; I have it set to 128 on my
> laptop.  I haven't checked to see if that affects such things as shared
> memory availability....  (I also tend to be fairly generous with swap
> space:  I prefer to avoid swapping, but if the system really needs to
> swap, I much prefer letting it do so to preventing that.)

Yes, I've also punched up MAXUSERS to 128, but that didn't fix things .
. . so then I tried the SysV settings, they worked . . . .  YMMV. 

jmc

> Cheers,
> david
> --
> David Wolfskill      dhw@whistle.com   UNIX System Administrator
> Desk: 650/577-7158   TIE: 8/499-7158   Cell: 650/759-0823

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?3AF1B90F.30DA4861>