Subject: Re: 7GB memtest causes hard system hang.
To: Chuck Silvers <>
From: Frank van der Linden <>
List: port-amd64
Date: 01/22/2006 12:45:27
On Wed, Jan 18, 2006 at 09:07:30AM -0800, Chuck Silvers wrote:
> On Mon, Jan 16, 2006 at 10:22:24PM +0100, Frank van der Linden wrote:
> this is also the cause of PR 32157, kmem_map fills up and then we go into
> an infinite loop trying to allocate more memory.
> is there any reason we shouldn't increase NKMEMPAGES_MAX_DEFAULT to 1 GB
> at this point?

It should probably be done, but I have seen one report of it causing
a problem early during boot. THis is from an older message (august
last year) about NetBSD 2.0.2:

Christopher A. Kantarjiev wrote:

> I've built up a dual dual-core Opteron machine with a lot of memory
> and have run into various panics. I'm running 2.0.2, and I have pretty
> much filled RAM with data that is mmap'd from disk files, accessed
> read-only by four processes.
> At first, the machine had 8GB and I didn't have much difficulty, but I
> would occasionally get
> panic: uvm_mapent_alloc: out of static map entries
> I bumped the static number to 2000 and the issue 'went away'.
> Then I added 8GB, total of 16GB, and had more fun:
> panic: pmap_enter: no pv entries available
> It was suggested that I bump NKMEMPAGES=100000, which I did, and got a
> quick 'trap 6' on boot! But I have NKMEMPAGES=60000 now, and I'm not
> getting that panic any more.
> But I continue to get
> panic: uvm_mapent_alloc: out of static map entries
> I have increased the static number to 8000, and pulled out 4GB (total
> 12GB at the moment), and the problem still exists; more annoyingly,
> the system doesn't crash cleanly (hangs while syncing disks). So we
> are rebooting every two days
> to avoid the hangs.
> I'd love to find a real fix for this. Is there a way to track the
> number of KMAPENT entries that are in use? vmstat doesn't seem to have
> an appropriate option.

- Frank