Subject: Re: MAX_KMAPENT?
To: Michael Gorsuch <mgorsuch@fogcreek.com>
From: Joseph A. Dacuma <jadacuma@ched.gov.ph>
List: netbsd-help
Date: 11/16/2006 03:59:12
> I have a NetBSD 2.0.1 box that died last night with the following error
> on the console:
>
> panic: uvm_mapent_alloc: out of static map entries, check MAX_KMAPENT
> (currently 1114)
> Stoppped in pid 15.1 (pagedaemon) at netbsd:cpu_Debugger+0x4
>
> Of course, things are fine after a reboot.
>
> Trying to be the good scientist, I need to get a better understanding of
> what 'MAX_KMAPENT' is and what 'uvm_mapent_alloc' is.  If anyone can
> help, I'd really appreciate it.
>
> I have to assume that there is some sort of resource issue going on
> here, and I don't want to just reboot the box and forget about it.
>
> Thanks so much,
>
> Michael
>

Hi Mr. Gorsuch!

You seem to have a very busy server. MAX_KMAPENT from what I understand is
the number of static entries in kmem map (kernel virtual memory). Things
are fine after reboot since your kernel memory map has been refreshed.

I had a similar problem before. What I did was fiddle between maxusers,
max kmapent, nkmempages. It helped me when I was still using 2.x but now
its different with my 3.x boxes as the in-kernel map entries are now
dynamically allocated. This was months ago so I really couldn't remember
in detail the magic numbers that worked for me.

HTH,

Joseph