Date: Mon, 18 May 2009 22:16:04 -0400 From: Adam McDougall <mcdouga9@egr.msu.edu> To: Kip Macy <kmacy@freebsd.org> Cc: current@freebsd.org, Larry Rosenman <ler@lerctr.org> Subject: Re: Fatal trap 12: page fault panic with recent kernel with ZFS Message-ID: <20090519021603.GT82547@egr.msu.edu> In-Reply-To: <3c1674c90905181903o281406fbia135c295738d73b5@mail.gmail.com> References: <20090518145614.GF82547@egr.msu.edu> <alpine.BSF.2.00.0905181031240.35767@thebighonker.lerctr.org> <alpine.BSF.2.00.0905181830490.1756@borg> <3c1674c90905181659g1d20f0f1w3f623966ae4440ec@mail.gmail.com> <alpine.BSF.2.00.0905181906001.2008@borg> <20090519012202.GR82547@egr.msu.edu> <3c1674c90905181826p787a346cie90429324444a9c4@mail.gmail.com> <20090519015713.GS82547@egr.msu.edu> <3c1674c90905181903o281406fbia135c295738d73b5@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
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 > boxes. 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.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20090519021603.GT82547>