Why kernel panic with NMI watchdog on RIP '__write_lock_failed' ?

Issue

• RHEL5 kernel panic with "NMI Watchdog detected LOCKUP" and RIP _write_lock_failed
• Here is the kernel log from one panic.

NMI Watchdog detected LOCKUP on CPU 6
CPU 6
Modules linked in: nfs fscache nfs_acl lockd sunrpc bonding ipt_REDIRECT xt_tcpudp iptable_nat ip_nat ip_conntrack nfnetlink ip_tables x_tables be2iscsi ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp bnx2i cnic ipv6 xfrm_nalgo crypto_api uio cxgb3i cxgb3 libiscsi_tcp libiscsi2 scsi_transport_iscsi2 scsi_transport_iscsi mptctl dm_multipath scsi_dh video backlight sbs power_meter hwmon i2c_ec dell_wmi wmi button battery asus_acpi acpi_memhotplug ac parport_pc lp parport sg tpm_tis i2c_i801 tpm i7core_edac bnx2 i2c_core edac_mc cdc_ether tpm_bios usbnet pcspkr dm_raid45 dm_message dm_region_hash dm_mem_cache dm_snapshot dm_zero dm_mirror dm_log dm_mod be2net(U) 8021q shpchp mptsas mptscsih mptbase scsi_transport_sas sd_mod scsi_mod ext3 jbd uhci_hcd ohci_hcd ehci_hcd
Pid: 7328, comm: oracle Tainted: G      2.6.18-238.9.1.el5 #1
RIP: 0010:[<ffffffff80062187>]  [<ffffffff80062187>] __write_lock_failed+0xf/0x20
RSP: 0018:ffff812f4a501aa8  EFLAGS: 00000083
RAX: 0000000000000000 RBX: ffff81012debac08 RCX: 00000000000000d0
RDX: ffff810f8a1bcbf8 RSI: ffff811ff6748570 RDI: ffff811ff6748588
RBP: ffff81012debac08 R08: ffff81108014fc0e R09: 0000000000c0eb9e
R10: 0000000000000000 R11: 0000000000000002 R12: ffff811ff6748570
R13: 0000000000000000 R14: 0000000000007508 R15: ffffffff886a691c
FS:  00002ba5d3a9ae30(0000) GS:ffff812080130440(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000d5a0000e CR3: 00000030303b5000 CR4: 00000000000006e0
Process oracle (pid: 7328, threadinfo ffff812f4a500000, task ffff812fba310080)
Stack:  ffffffff80064b73 ffffffff8000c853 ffff81012debac08 ffff81012debac08
 ffff811ff6748570 0000000000000000 ffff812f4a501b68 ffffffff800c805c
 ffff810f8a1bcbf8 ffff81012debac08 ffff812f4a501be8 ffffffff8004db53
Call Trace:
 [<ffffffff80064b73>] _write_lock_irq+0xf/0x10
 [<ffffffff8000c853>] add_to_page_cache+0x30/0xc1
 [<ffffffff800c805c>] add_to_page_cache_lru+0xe/0x22
 [<ffffffff8004db53>] read_cache_pages+0x47/0xc8
 [<ffffffff886a70fb>] :nfs:nfs_readpages+0x209/0x2e9
 [<ffffffff80013070>] __do_page_cache_readahead+0xfc/0x179
 [<ffffffff800325ce>] blockable_page_cache_readahead+0x53/0xb2
 [<ffffffff8001414b>] page_cache_readahead+0x13d/0x1af
 [<ffffffff8000c374>] do_generic_mapping_read+0xc6/0x359
 [<ffffffff8000d279>] file_read_actor+0x0/0x159
 [<ffffffff8000c753>] __generic_file_aio_read+0x14c/0x198
 [<ffffffff80016efc>] generic_file_aio_read+0x34/0x39
 [<ffffffff8000cfa2>] do_sync_read+0xc7/0x104
 [<ffffffff800a28f3>] autoremove_wake_function+0x0/0x2e
 [<ffffffff8000b78d>] vfs_read+0xcb/0x171
 [<ffffffff800136e9>] sys_pread64+0x3a/0x70
 [<ffffffff800136ff>] sys_pread64+0x50/0x70
 [<ffffffff8005d116>] system_call+0x7e/0x83

Code: 75 f6 f0 81 2f 00 00 00 01 0f 85 e2 ff ff ff c3 90 f0 ff 07