kmem leak in tmpmfs?

Iasen Kostov tbyte at
Fri May 26 03:26:41 PDT 2006

On Thu, 2006-05-25 at 16:54 -0400, Kris Kennaway wrote:
> On Thu, May 25, 2006 at 06:01:30PM +0200, Arno J. Klaassen wrote:
> > Hello,
> > 
> > I get a very easy to reproduce panic on 6.1-STABLE :
> > 
> > /etc/periodic/weekly/310.locate panics with
> > 
> >   panic: kmem_malloc(4096): kmem_map too small: 335544320 total allocated
> It looks like you are using a malloc-backed md and you do not have
> enough RAM to handle the size.  Perhaps tmpmfs does not use swap
> backing, as it is supposed to?
> Kris

	First of all if there is not enough kmem (not just plain ram I think)
kernel should not allow disk creation in first place, second - I think
(although there could be some ... reason for that) it's stupid way to
say "I don't have more kmem" by panicing :). Better way will be just to
fail disk operation of that FS with "Disk is full" or something like
that. At home I tried to raise kmem like that:
"vm.kmem_size_max="1073741824" (I got 2G of RAM)
(setting vm.kmem_size directly panices kernel at boot if I remember

but for my surprise kernel panices at exact same allocated md disk space
with the same panic as the original poster's. Is it possible that I
should rise KVA_PAGES too ? And I don't think its documented anywhere
(of course I've tried googling and it's always possible that I've missed
something :). All this was on FreeBSD 6.0.

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