Tracking down what has inact pages locked up

[John Baldwin]

On Tuesday, March 18, 2014 3:36:04 pm Karl Denninger wrote:
> 
> On 3/18/2014 2:05 PM, John Baldwin wrote:
> > On Sunday, March 16, 2014 4:36:06 pm Karl Denninger wrote:
> >> Is there a reasonable way to determine who or what has that memory
> >> locked up -- and thus why the vm system is not demoting that space into
> >> the cache bucket so it can be freed (which, if my understanding is
> >> correct, should be happening long before now!)
> > I have a hackish thing (for 8.x, might work on 10.x) to let you figure out
> > what is using up RAM.  This should perhaps go into the base system at some
> > point.
> >
> > Grab the bits at http://people.freebsd.org/~jhb/vm_objects/
> >
> > You will want to build the kld first and use 'make load' to load it.  It adds
> > a new sysctl that dumps info about all the VM objects in the system.  You can
> > then build the 'vm_objects' tool and run it.  It can take a while to run if
> > you have NFS mounts, so I typically save its output to a file first and then
> > use sort on the results.  sort -n will show you the largest consumer of RAM,
> > sort -n -k 3 will show you the largest consumer of inactive pages.  Note
> > that 'df' and 'ph' objects are anonymous, and that filename paths aren't
> > always reliable, but this can still be useful.
> >
> Thanks.
> 
> I suspect the cause of the huge inact consumption is a RAM leak in the 
> NAT code in IPFW.  It was not occurring in 9.2-STABLE, but is on 
> 10.0-STABLE, and reverting to natd in userland stops it -- which 
> pretty-well isolates where it's coming from.

Memory for in-kernel NAT should be wired pages, not inactive.

-- 
John Baldwin