Re: Out of memory debug

[mlelstv%serpens.de@localhost (Michael van Elst)]

manu%netbsd.org@localhost (Emmanuel Dreyfus) writes:

>Running bt/a c6f1f980 at various times shows pageadaemon is alive. Is
>it just that the system is out of memory, and nothing can be reclaimed? 
>There is no swap configured.


The system is waiting for kernel memory. On 32bit systems
that can be more limited than physical memory.

pgdaemon is spinning because no memory gets freed (there are already
free pages) and no KVA space is released, by spinning it also slows
down the process of freeing memory.

Usually there is some unused memory by the vnode cache and
associated data. Reducing desiredvnodes (in DDB) which is the
same as the sysctl item kern.maxvnodes can revive the system,
but of course that doesn't solve the problem.