Subject: Re: kernel limits (??)
To: Frank van der Linden <email@example.com>
From: Mark Allman <firstname.lastname@example.org>
Date: 10/14/1998 08:49:04
I forgot some information, apparently... Here are answers to some
of the question/suggestions raised.
> o What is the stack backtrace from the panic/crash? That could
> be valuable to know when diagnosing this.
Not sure. I am not all that good with the kernel debugger. I'll
try to figure out how to get this...
> o Which version of NetBSD are we talking about (if we're talking
> some version of -current, the source date could be useful to
> o Are you using UVM?
Not on purpose. If it is on by default, I am using it. Otherwise,
I am not.
> My initial guess is that you could be running out of some kernel
> resource used for the buffer management of the TCP sessions (?).
I have plenty of mbufs, see below.
> Are all the processes "active" in pushing out data, or are they
> low-bandwidth connections, not likely to consume a significant
> amount of their buffer needs?
Each process starts, sets up a TCP connection, transmits some amount
of data as quickly as possible, closes the connection and then
> You probably need an increase in NMBCLUSTERS. Compiler a kernel with
> options NMBCLUSTERS=2048
> and try it again.
Sorry, I should have noted that I have done that... From my kernel
options NKMEMCLUSTERS="(18 * 1024 * 1024/CLBYTES)"
This provides plenty of mbufs for ~200 connections (each with a 16
KB socket buffer). I have run up against the mbuf limit before and
I get an mb_map_full (or something like that) error message (not
panic). I was pretty careful about making sure that I had enough
mbufs, so I don't think that is the problem.
> try increasing MAX_KMAPENT (defined in vm/vm_map.h) a bit. i
> suspect you are running out of kernel map entries.
This is one I have not tried... I'll give it a shot.
Thanks for all the help! We appreciate it!