different CM panic (was: [openib-general] completion Q overflow error/panic)

[Roland Dreier]

No time to analyze this just now, but trying to run Viswa's test, I
got the following CM panic:

[ 3335.553628] Unable to handle kernel paging request at 000000013a7f0e18 RIP:
[ 3335.567573] <ffffffff801da208>{rb_erase+213}
[ 3335.587832] PGD 13cc64067 PUD 0
[ 3335.597568] Oops: 0000 [1] SMP
[ 3335.607051] CPU 3
[ 3335.613110] Modules linked in: ib_uat ib_at ib_ucm ib_cm ib_uverbs ib_ipoib ib_sa ib_mthca ib_mad ib_core nfsd exportfs ipv6 nfs lockd sunrpc ehci_hcd ohci_hcd i2c_nforce2 i2c_core tg3 psmouse ide_generic ide_disk unix
[ 3335.671837] Pid: 3050, comm: ib_cm/3 Not tainted 2.6.13
[ 3335.687608] RIP: 0010:[<ffffffff801da208>] <ffffffff801da208>{rb_erase+213}
[ 3335.708115] RSP: 0018:ffff81007e1fbd10  EFLAGS: 00010006
[ 3335.724688] RAX: ffff8101382b3200 RBX: ffff81013a7f0e00 RCX: ffff8101382b3200
[ 3335.746243] RDX: 0000000000000000 RSI: 000000013a7f0e00 RDI: ffff81013a7f0f08
[ 3335.767791] RBP: 0000000000000082 R08: ffffffff881da2b8 R09: 0000000002e97c10
[ 3335.789347] R10: ffff81013a7f0f00 R11: ffff81007e67c800 R12: 0000000000000008
[ 3335.810891] R13: 0000000000000000 R14: 0000000000000000 R15: ffff81013ff74518
[ 3335.832422] FS:  00002aaaab2c5700(0000) GS:ffffffff804cc980(0000) knlGS:0000000000000000
[ 3335.856872] CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
[ 3335.874220] CR2: 000000013a7f0e18 CR3: 000000013eb56000 CR4: 00000000000006e0
[ 3335.895767] Process ib_cm/3 (pid: 3050, threadinfo ffff81007e1fa000, task ffff8100bfe9e2f0)
[ 3335.920986] Stack: ffffffff881d0862 ffff81007e67c800 ffff8101382b3200 0000000000000000
[ 3335.944670]        ffffffff881d098e ffff8101382b3200 ffffffff881d2ee5 0000000000000000
[ 3335.968894]        0000000000000287 00000004382b30e8
[ 3335.984157] Call Trace:<ffffffff881d0862>{:ib_cm:cm_cleanup_timewait+60} <ffffffff881d098e>{:ib_cm:cm_reset_to_idle+28}
[ 3336.016783]        <ffffffff881d2ee5>{:ib_cm:ib_send_cm_rej+174} <ffffffff881d0aa0>{:ib_cm:ib_destroy_cm_id+249}
[ 3336.047562]        <ffffffff802cf8f4>{_read_unlock_irqrestore+5} <ffffffff881d0299>{:ib_cm:cm_init_av_by_path+115}
[ 3336.078857]        <ffffffff881d1de6>{:ib_cm:cm_req_handler+1050} <ffffffff881d469b>{:ib_cm:cm_work_handler+0}
[ 3336.109107]        <ffffffff881d46ba>{:ib_cm:cm_work_handler+31} <ffffffff8013f545>{worker_thread+424}
[ 3336.137279]        <ffffffff8012bbb2>{default_wake_function+0} <ffffffff8012bbb2>{default_wake_function+0}
[ 3336.166478]        <ffffffff801431df>{keventd_create_kthread+0} <ffffffff8013f39d>{worker_thread+0}
[ 3336.193836]        <ffffffff801431df>{keventd_create_kthread+0} <ffffffff801431b6>{kthread+129}
[ 3336.220142]        <ffffffff8010e45e>{child_rip+8} <ffffffff801431df>{keventd_create_kthread+0}
[ 3336.246451]        <ffffffff80143135>{kthread+0} <ffffffff8010e456>{child_rip+0}
[ 3336.268811]
[ 3336.275661]
[ 3336.275662] Code: 48 39 7e 18 75 06 48 89 4e 18 eb 09 48 89 4e 10 eb 03 49 89