Date: Wed, 17 Aug 2011 23:00:12 -0400 (EDT) From: Benjamin Kaduk <kaduk@MIT.EDU> To: John <jwd@freebsd.org> Cc: freebsd-fs@freebsd.org, freebsd-current@freebsd.org Subject: Re: Three LOR with latest -current Message-ID: <alpine.GSO.1.10.1108172256550.7526@multics.mit.edu> In-Reply-To: <20110816040519.GA49864@FreeBSD.org> References: <20110816040519.GA49864@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Hello John, These seem to be well-known, per http://ipv4.sources.zabbadoz.net/freebsd/lor.html On Tue, 16 Aug 2011, John wrote: > Hi folks, > > I'm seeing 3 lock order reversals with an up-to-date -current > system. Stock system, GENERIC kernel. Let me know if this isn't > enough information. Just booting the system and the dmesg. > > Thanks, > John > > > lock order reversal: > 1st 0xfffffe0289627db8 ufs (ufs) @ /usr/src.2011-08-14_10.53pm_EDT/sys/ufs/ffs/ffs_snapshot.c:425 > 2nd 0xffffff9f0db49778 bufwait (bufwait) @ /usr/src.2011-08-14_10.53pm_EDT/sys/kern/vfs_bio.c:2658 > 3rd 0xfffffe00404a8098 ufs (ufs) @ /usr/src.2011-08-14_10.53pm_EDT/sys/ufs/ffs/ffs_snapshot.c:546 This looks like #285. > > > lock order reversal: > 1st 0xffffff9f0db49778 bufwait (bufwait) @ /usr/src.2011-08-14_10.53pm_EDT/sys/kern/vfs_bio.c:2658 > 2nd 0xfffffe004034dcb0 snaplk (snaplk) @ /usr/src.2011-08-14_10.53pm_EDT/sys/ufs/ffs/ffs_snapshot.c:818 The line numbers are a bit off, but this could be #269. > > > lock order reversal: > 1st 0xfffffe004034dcb0 snaplk (snaplk) @ /usr/src.2011-08-14_10.53pm_EDT/sys/kern/vfs_vnops.c:301 > 2nd 0xfffffe0289627db8 ufs (ufs) @ /usr/src.2011-08-14_10.53pm_EDT/sys/ufs/ffs/ffs_snapshot.c:1620 And this would be #240. Since they are so commonly reported (but no deadlocks have been attributed to them), it seems likely that they are harmless. Perhaps we should tell WITNESS to not warn about them ... -Ben Kaduk
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?alpine.GSO.1.10.1108172256550.7526>