panic: kmem_malloc(16384): kmem_map too small: md-mounted /tmp filled up

Mikhail Teterin mi+kde at
Tue Feb 27 19:48:16 UTC 2007

On Tuesday 27 February 2007 11:41, Alex Kozlov wrote:
= On Tue, Feb 27, 2007 at 10:59:08AM -0500, Mikhail Teterin wrote:
= > /tmp's space allocation (after reboot) is as follows:
= > 
= >   Filesystem 1K-blocks Used   Avail Capacity  Mounted on
= >   /dev/md0     2026030 3552 1860396     0%    /tmp
= > 
= > Note, that it is supposed to hold 2Gb, but was filled up and paniced
= > holding about 300Mb... Probably, because it is created with ``-M''
= > by default -- but it is not supposed to panic anyway!
= You may want to set -o reserve option. Or better, switch to a swap backed
= md.

Yes, I switched to swap-backed md already. But the malloc-based variety is 
currently the _default_ (see /etc/defaults/rc.conf)...

Creation of a 2Gb malloc-based md should've failed on a machine with 768Mb of 
RAM, shouldn't it have?

On Tuesday 27 February 2007 11:45, Zaphod Beeblebrox wrote:
= IIRC, the total kernel memory on a normally configured 6.xor 7.x box is 1G
= on 32 bit.
= So I've pretty much abandoned ram disks on 32 bit machines.  Not enough
= memory.

Memory "disks" used to be served by user-space processes (mount_mfs), making 
them not care for the whole malloc/swap distinctions, and the address-space 

Are you sure, swap-based mds still consume kernel's address space, though?


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