Hi list, We have 2 freebsd 8.2-STABLE (cvsuped june 22) that keeps crashing in a bad way :
The are doing heavy apache / php4 web serving from a nfs mount and panic at least once a day with the following message (no crash dump produced, hand copied from the console) : Sleeping on "vmopar" with the following non-sleepable locks held: exclusive sleep mutex NFSnode lock (NFSnode lock) r = 0 (0xffffff0201798000) locked @ nfsclient/nfs_subs.c:538 lock order reversal: 1st 0xffffffff018ff6da80 turnstile lock (turnstile lock) @ kern/subr_turnstile.c:190 2nd 0xffffffffff80b52b10 scrlock (scrlock) @ dev/syscons.c:2570 lock order reversal: 1st 0xffffffff018ff6da80 turnstile lock (turnstile lock) @ kern/subr_turnstile.c:190 2nd 0xffffffffff80b78ef8 sleepq chain (sleepq chain) @ kern/subr_turnstile.c:203 lock order reversal: 1st 0xffffffffff80b78ef8 sleepq chain (sleepq chain) @ kern/subr_turnstile.c:203 2nd 0xffffffffff80b52b10 scrlock (scrlock) @ dev/syscons.c:2570 Sleeping thread (tid 100998, pid 20700) owns a non-sleepable lock panic: sleeping thread cpuid = 1 panic: bufwrite: buffer is not busy??? cpuid = 1 The 2 servers share the same load and panic consistently. I enabled WITNESS on the 2 in the hope it would allow the boxes to auto reboot after panic and get extra debug info. I got debug info but the servers still hangs after the double panic :( I also noticed that immediately after rebooting following this panic, I got the following LORs (approximatively at the time rc.d is launching ports like apache & co) lock order reversal: 1st 0xffffff81ee00e388 bufwait (bufwait) @ kern/vfs_bio.c:2636 2nd 0xffffff0006e56c00 dirhash (dirhash) @ ufs/ufs/ufs_dirhash.c:285 lock order reversal: 1st 0xffffff0009c709e0 so_snd_sx (so_snd_sx) @ kern/uipc_sockbuf.c:145 2nd 0xffffff0124282620 ufs (ufs) @ kern/uipc_syscalls.c:2086 lock order reversal: 1st 0xffffff0009c709e0 so_snd_sx (so_snd_sx) @ kern/uipc_sockbuf.c:145 2nd 0xffffff01243569d0 nfs (nfs) @ kern/uipc_syscalls.c:2086 The server continued to work despite the lors so I don't know if this is related to the panics or not. What can I do from there to debug this further ? Regards, -- Herve Boulouis _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
