Date: Wed, 14 Dec 2005 17:32:34 +0100 From: Fabian Keil <freebsd-listen@fabiankeil.de> To: Scott Long <scottl@samsco.org> Cc: Gleb Smirnoff <glebius@freebsd.org>, freebsd-stable@freebsd.org Subject: Re: FreeBSD 6.0 panic: kmem_malloc(16384): kmem_map too small: 172728320 total allocated [solved] Message-ID: <20051214173234.4bb5ffb9@TP51.local> In-Reply-To: <43A03CFC.6070406@samsco.org> References: <20051214132530.3b6daecd@TP51.local> <20051214131855.GH59644@FreeBSD.org> <43A03CFC.6070406@samsco.org>
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[-- Attachment #1 --] Scott Long <scottl@samsco.org> wrote: > Gleb Smirnoff wrote: > > > On Wed, Dec 14, 2005 at 01:25:30PM +0100, Fabian Keil wrote: > > F> I triggered a few reproducible panics on FreeBSD 6.0-STABLE. > > F> > > F> I created a ramdisk with: > > F> > > F> /sbin/mdconfig -a -t malloc -s 256M -u 10 > > F> /sbin/newfs -U /dev/md10 > > F> /sbin/mount /dev/md10 /mnt/ramdisk > > F> > > F> The system has "avail memory = 515932160 (492 MB)" > > F> and 1GB swap space. > > F> > > F> While copying to /mnt/ramdisk trough ftp localhost > > F> it got: > > > > This usually exposes some memory leak in kernel. Can you please do > > the following - copy some amount of data to /mnt/ramdisk trough ftp > > localhost, and cancel the operation before it panics. > > > > Then run vmstat -m and vmstat -z, to determine what kind of memory > > allocation is leaking. > > > > > > While it can mean a memory leak in the kernel, I don't think that's > the case here. > On i386, only 320MB can be allocated to kernel malloc memory. Much > of this space > can get consumed with vnodes and other filesystem structures, so > trying to allocate > 256MB to a ramdisk is likely putting you over the max. I'd suggest > instead to use > a swap-back disk. It doesn't necessarily mean that the ramdisk pages > will live in > swap, it just means that they will get managed directly in the > bufcache, eliminating > the 320MB restriction. I guess you're right. I can fill a 256MB swap-backed disk without panic and without swapping. Before ftp localhost: last pid: 652; load averages: 0.02, 0.09, 0.07 up 0+00:07:16 17:12:05 37 processes: 1 running, 36 sleeping CPU states: 0.0% user, 0.0% nice, 0.0% system, 0.4% interrupt, 99.6% idle Mem: 11M Active, 12M Inact, 18M Wired, 11M Buf, 453M Free Swap: 999M Total, 999M Free After ftp localhost: last pid: 666; load averages: 0.20, 0.12, 0.08 up 0+00:09:05 17:13:54 36 processes: 1 running, 35 sleeping CPU states: 0.0% user, 0.0% nice, 0.0% system, 0.4% interrupt, 99.6% idle Mem: 244M Active, 150M Inact, 73M Wired, 27M Cache, 60M Buf, 984K Free Swap: 999M Total, 999M Free After removal of the swap-backed disk: last pid: 690; load averages: 0.00, 0.01, 0.03 up 0+00:17:53 17:22:42 34 processes: 1 running, 33 sleeping CPU states: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle Mem: 15M Active, 76M Inact, 43M Wired, 13M Cache, 60M Buf, 347M Free Swap: 999M Total, 999M Free Thanks for your time Gleb and Scott. Fabian -- http://www.fabiankeil.de/ [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (FreeBSD) iD8DBQFDoEk7jV8GA4rMKUQRAiU9AKCxxVRrnuGW1/RBE94c5a6klL5N6QCgutnB GOB5wVzdwaFJC+Z5imlLQ8E= =xqEn -----END PGP SIGNATURE-----help
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