Date: Thu, 04 Dec 2008 05:12:04 +0200 From: Giorgos Keramidas <keramida@ceid.upatras.gr> To: Kevin Monceaux <Kevin@RawFedDogs.net> Cc: FreeBSD Questions E-Mail List <FreeBSD-Questions@freebsd.org> Subject: Re: Returning User With Filesystem/Memory Tuning Questions Message-ID: <87abbciqgr.fsf@kobe.laptop> In-Reply-To: <alpine.LNX.2.00.0812031659260.29569@Blaidd-Drwg.RawFedDogs.net> (Kevin Monceaux's message of "Wed, 3 Dec 2008 17:24:48 -0600 (CST)") References: <alpine.LNX.2.00.0812031230460.29569@Blaidd-Drwg.RawFedDogs.net> <20081203202155.GA84629@slackbox.xs4all.nl> <alpine.LNX.2.00.0812031659260.29569@Blaidd-Drwg.RawFedDogs.net>
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On Wed, 3 Dec 2008 17:24:48 -0600 (CST), Kevin Monceaux <Kevin@RawFedDogs.net> wrote:
> On Wed, 3 Dec 2008, Roland Smith wrote:
>
>> Application crashed can also be due to bad hardware, especially
>> memory. Make sure that you rule out hardware troubles before diving
>> into the software.
>
> I don't think it was hardware related, but it's a possibility.
>
> Jogging my memory a bit more I think the first program I had memory
> allocation problems was tin. Fetching headers from even a semi-large
> newsgroup would cause tin to crash. I forget the exact error messages
> but they were something along the lines of not being able to allocate
> the needed amount of memory. At the times of the failures there
> appeared to be available RAM with swap space completely untouched. The
> errors occurred at about the same point in fetching the headers each
> time. After much Googling I tried adjusting the following:
>
> kern.maxdsiz
> kern.dfldsiz
> kern.maxssiz
Hi Kevin,
The `kern.maxdsiz' tunable is a boot-time option that limits the amount
of memory a _single_ process can allocate for its `data'. The default
value is 512 MB (the value reported by sysctl is the number of bytes):
$ sysctl kern.maxdsiz
kern.maxdsiz: 536870912
If a single process running on i386 wants to allocate more than 512 MB
of memory, and it is not a large database server, then it's possible
that something is wrong with the way the process handles its memory :)
For what it's worth, I've been reading newsgroups with more than 5000
messages in Gnus, a newsreader that runs inside GNU Emacs, and its
memory usage has *never* reached 512 MB, so if you want help to switch
from the aging tin reader to something that is still maintained &
developed actively, I will be glad to help. Gnus can run in text-only
mode too, much like tin; it supports threading, scoring of messages by
author, subject, by custom header filters, etc.; it can read messages
from multiple news servers; it can work in `offline' mode and post all
your outgoing messages later, when you get back online; it can prefetch
all the messages of your favorite groups, and that's just a short list
of the features I can remember off-hand.
> which greatly improved things. But, I adjusted them using examples of
> values I found on the net without really understanding what I was
> doing. This time around I want to learn how to tweak whatever settings
> need to be tweaked to best use my available memory.
Well, you can just ask here, on the freebsd-questions list. There are
_many_ knowledgeable subscribers who can describe what each FreeBSD
option means, how to tune it for your own needs, and so on :-)
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