Hi,

we are currently testing CEPH with RBD on a cluster with 1GBit and
10Gbit interfaces. While we see no kernel crashes with RBD if the
cluster runs on the 1GBit interfaces, we see very frequent kernel
crashes with the 10Gbit network while running tests with e.g. fio
against the RBDs.

I've tested it with kernel v3.0 and also 3.3.0 (with the patches from
the 'for-linus' branch from ceph-client.git at git.kernel.org).

With more client machines running tests the crashes occur even much
faster. The issue is fully reproducible here.

Has anyone seen similar problems? See the backtrace below.

Regards

Danny

PID: 10902  TASK: ffff88032a9a2080  CPU: 0   COMMAND: "kworker/0:0"
 #0 [ffff8803235fd950] machine_kexec at ffffffff810265ee
 #1 [ffff8803235fd9a0] crash_kexec at ffffffff810a3bda
 #2 [ffff8803235fda70] oops_end at ffffffff81444688
 #3 [ffff8803235fda90] __bad_area_nosemaphore at ffffffff81032a35
 #4 [ffff8803235fdb50] do_page_fault at ffffffff81446d3e
 #5 [ffff8803235fdc50] page_fault at ffffffff81443865
    [exception RIP: read_partial_message+816]
    RIP: ffffffffa041e500  RSP: ffff8803235fdd00  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: 00000000000009d7  RCX: 0000000000008000
    RDX: 0000000000000000  RSI: 00000000000009d7  RDI: ffffffff813c8d78
    RBP: ffff880328827030   R8: 00000000000009d7   R9: 0000000000004000
    R10: 0000000000000000  R11: ffffffff81205800  R12: 0000000000000000
    R13: 0000000000000069  R14: ffff88032a9bc780  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #6 [ffff8803235fdd38] thread_return at ffffffff81440e82
 #7 [ffff8803235fdd78] try_read at ffffffffa041ed58 [libceph]
 #8 [ffff8803235fddf8] con_work at ffffffffa041fb2e [libceph]
 #9 [ffff8803235fde28] process_one_work at ffffffff8107487c
#10 [ffff8803235fde78] worker_thread at ffffffff8107740a
#11 [ffff8803235fdee8] kthread at ffffffff8107b736
#12 [ffff8803235fdf48] kernel_thread_helper at ffffffff8144c144