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

Mikhail Teterin mi+kde at
Tue Feb 27 21:03:32 UTC 2007

On Tuesday 27 February 2007 15:53, Alex Kozlov wrote:
= > Yes, I switched to swap-backed md already. But the malloc-based variety is 
= > currently the _default_ (see /etc/defaults/rc.conf)...
= Bad default.

Filing a PR.

= > Creation of a 2Gb malloc-based md should've failed on a machine with
= > 768Mb of RAM, shouldn't it have?
= Only if you set '-o reserve'. Memory for malloc-based md was allocated
= dynamically.

But malloc can only allocate from RAM, right? So the amount of RAM is the hard 
limit, which a malloc-based md can not exceed even in theory. This means, 
md-creation should've failed...

In fact, the limit should, of course, be even lower -- and mdmfs should be 
smart enough to substract the sizes of other kernel memory chunks from the 

Since even that would still not be a guarantee against running out, the system 
should be able to recover gracefully instead of panicing. Do you agree?


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