Fatal trap 12: page fault panic with recent kernel with ZFS
mcdouga9 at egr.msu.edu
Tue May 19 02:16:05 UTC 2009
On Mon, May 18, 2009 at 07:03:45PM -0700, Kip Macy wrote:
> Thanks, I appreciate all this work. ?Not allowing inactive pages to
> shrink the ARC sounds great as an option. ?I would be willing to bet
> that allowing inactive pages to shrink the arc would be far less
> detrimental to most people who aren't running a constant busy file
> server load, and its definitely important to try to protect untuned
Allowing NFS to use ARC buffers might be one solution to that.
That would be interesting. I haven't used ZFS for any NFS serving
yet though. With my mix of userspace file serving daemons my Inactive
mem just rises 1-3M/sec until almost all free memory is consumed and
I don't know why. None of the processes in top or ps can account for
16G of Inactive.
> Do you have any suggestions for increasing the amount of memory ARC
> can use? ?I've had difficulty increasing kmem past a few gigs on any
> of my recent builds (all past where kmem was changed so it could be
> more than ~2g) because at some point the kernel would stop booting.
> If I increase them too far, a few lines of the booting kernel would
> print, followed by a long stream of page fault panics or something
> with a sudden reboot. ?With the recent change allowing the use of
> direct mem, the ARC could easily use ample memory except it turned
> out not to be stable.
As of r192216 that should not be a probably any more. The maximum kmem
is now 512GB. It will be at least a year or two before anyone bumps
his head against that.
Ahh oops, I mistakenly thought it was backed out a few minutes ago
but that was something else. I guess that gives me something else I
can test. A number of changes went in recently and it was hard to tell
which commits were causing which symptoms.
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