On Fri, Apr 4, 2014 at 1:08 PM, Ilya Dryomov <ilya.dryomov@xxxxxxxxxxx> wrote: > On Wed, Apr 2, 2014 at 12:18 AM, Hannes Landeholm <hannes@xxxxxxxxxxxxxx> wrote: >> Hello, >> >> We're running a couple of Arch Linux servers of version 3.13.5-1 in >> production and suddenly one of them had a strange problem after >> running for a few days. One process (pid 319) was running with a few >> threads, one of those threads (pid 322) was eating 100% cpu. I assumed >> it was stuck in an infinite loop (this was our own software so I >> assumed we had a bug) so I sent a SIGKILL to 319 which caused all >> other threads to exit and it turning into a zombie, but thread 322 was >> still running. After trying to stop some other services and failing I >> realized that sending any signals to any process now didn't work at >> all in the system. >> >> This was the process stack output: >> >> $ cat /proc/319/stack >> [<ffffffff810642fa>] do_exit+0x73a/0xa80 >> [<ffffffff810646bf>] do_group_exit+0x3f/0xa0 >> [<ffffffff81073295>] get_signal_to_deliver+0x295/0x5f0 >> [<ffffffff810144a8>] do_signal+0x48/0x950 >> [<ffffffff81014e18>] do_notify_resume+0x68/0xa0 >> [<ffffffff8152326a>] int_signal+0x12/0x17 >> [<ffffffffffffffff>] 0xffffffffffffffff >> $ cat /proc/319/task/322/stack >> [<ffffffff8151c11a>] error_exit+0x2a/0x60 >> [<ffffffffffffffff>] 0xffffffffffffffff >> >> We're using ceph + rbd and this happened right after doing a rbd >> mapping (mounting it) or during the mapping itself, so we suspected >> rbd. >> >> A few days later (today) we had a server crash in another server, same >> version+distro and it had also just been running a few days as well. >> After starting it again we found the following in the system log: >> >> hostname kernel: BUG: unable to handle kernel paging request at ffff87fff75ad450 >> hostname kernel: IP: [<ffffffffa018c196>] rbd_img_request_fill+0x126/0x930 [rbd] > > Can you try gdb'ing that exact rbd.ko and > > (gdb) list *rbd_img_request_fill+0x126 > > Also, the entire stack trace pertaining to rbd_img_request_fill would > help. > > Thanks, > > Ilya Sorry, rbd was not built with any symbols and there was no other output in the journal. We're building a debug version of Linux 3.14 (with symbols) now that is currently being tested and we hope that we can roll it out today. I saw that at least one commit (638c323 rbd: drop an unsafe assertion) looks like something that could fix a crash that has been happening regularly on one of our development servers: http://i.imgur.com/pEKsmql.jpg (rbd_img_obj_callback in the stack trace). It might be related to the production crash we had. If we continue to get kernel panics we should at least be able to provide a proper stack trace in the future. Thank you for your time, Hannes -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
