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Description of problem: [ 794.990455] =================================================== [ 794.997970] [ INFO: suspicious rcu_dereference_check() usage. ] [ 795.003965] --------------------------------------------------- [ 795.009965] include/net/dst.h:91 invoked rcu_dereference_check() without protection! [ 795.017774] [ 795.017775] other info that might help us debug this: [ 795.017775] [ 795.025972] [ 795.025972] rcu_scheduler_active = 1, debug_locks = 0 [ 795.032634] 4 locks held by kworker/u:0/5: [ 795.036794] #0: ((name)){.+.+.+}, at: [<ffffffff81075a61>] process_one_work+0x14d/0x3e7 [ 795.045556] #1: ((&port_priv->work)){+.+.+.}, at: [<ffffffff81075a61>] process_one_work+0x14d/0x3e7 [ 795.055559] #2: (rcu_read_lock_bh){.+....}, at: [<ffffffff814185eb>] dev_queue_xmit+0x0/0x618 [ 795.065110] #3: (_xmit_INFINIBAND){+.-...}, at: [<ffffffff814307b6>] sch_direct_xmit+0x4e/0x14e [ 795.074831] [ 795.074831] stack backtrace: [ 795.079736] Pid: 5, comm: kworker/u:0 Tainted: G W 3.1.0-0.rc3.git0.0.fc16.x86_64 #1 [ 795.088759] Call Trace: [ 795.091493] [<ffffffff8108ca23>] lockdep_rcu_dereference+0xa7/0xaf [ 795.098019] [<ffffffffa0083a0d>] dst_get_neighbour+0x52/0x5a [ib_ipoib] [ 795.105005] [<ffffffffa0084568>] ipoib_start_xmit+0x3a/0x3b8 [ib_ipoib] [ 795.112000] [<ffffffff814184b6>] dev_hard_start_xmit+0x44f/0x584 [ 795.118355] [<ffffffff814307da>] sch_direct_xmit+0x72/0x14e [ 795.124294] [<ffffffff814189e0>] dev_queue_xmit+0x3f5/0x618 [ 795.130233] [<ffffffff814185eb>] ? dev_hard_start_xmit+0x584/0x584 [ 795.136756] [<ffffffff8108f439>] ? trace_hardirqs_on_caller+0x121/0x158 [ 795.143743] [<ffffffffa0084293>] path_rec_completion+0x30d/0x35e [ib_ipoib] [ 795.151062] [<ffffffffa0069000>] ib_sa_path_rec_callback+0x51/0x75 [ib_sa] [ 795.158292] [<ffffffffa006833b>] recv_handler+0x41/0x4d [ib_sa] [ 795.164585] [<ffffffffa0051d7e>] ib_mad_completion_handler+0x44d/0x643 [ib_mad] [ 795.172468] [<ffffffff8108b885>] ? trace_hardirqs_off+0xd/0xf [ 795.178598] [<ffffffffa0051931>] ? ib_mad_send_done_handler+0x157/0x157 [ib_mad] [ 795.186548] [<ffffffff81075b19>] process_one_work+0x205/0x3e7 [ 795.192664] [<ffffffff81075a61>] ? process_one_work+0x14d/0x3e7 [ 795.198958] [<ffffffff8108ceeb>] ? lock_acquired+0x210/0x243 [ 795.204991] [<ffffffff810767c7>] worker_thread+0xda/0x15d [ 795.210745] [<ffffffff810766ed>] ? manage_workers+0x176/0x176 [ 795.216865] [<ffffffff8107a18d>] kthread+0xa8/0xb0 [ 795.222014] [<ffffffff8150d284>] kernel_thread_helper+0x4/0x10 [ 795.228215] [<ffffffff815046f4>] ? retint_restore_args+0x13/0x13 [ 795.234578] [<ffffffff8107a0e5>] ? __init_kthread_worker+0x5a/0x5a [ 795.241121] [<ffffffff8150d280>] ? gs_change+0x13/0x13 Version-Release number of selected component (if applicable): kernel-3.1.0-0.rc3.git0.0.fc16.x86_64 How reproducible: Always Steps to Reproduce: 1. Ping a host over IPoIB
is this still happening with the latest update (you'll likely need the kernel-debug variant installed to check)
As far as I can tell, this is fixed on kernel-debug 3.2.7-1.
(In reply to comment #2) > As far as I can tell, this is fixed on kernel-debug 3.2.7-1. "Fixed" is the wrong resolution I think. The IOMMU was disabled by default. If you boot with iommu=on and a kernel-debug kernel, it will probably show back up.
Sorry, I wanted to mention that. What is the future of the IOMMU stuff? Why was it disabled in 3.1.6? There are other IB bugs that also trigger with the IOMMU enabled, but I don't know if we should be reporting them if the default is to disable it.
[mass update] kernel-3.3.0-4.fc16 has been pushed to the Fedora 16 stable repository. Please retest with this update.
looks fixed
(In reply to comment #8) > looks fixed Just to clarify, you tested kernel-debug-3.3.0-4.fc16 and specified iommu=on on the kernel command line?
That is correct.
Thanks Albert.