boot time crash when kdump is enabled on box with 256GB memory in RHEL 5

Issue

• System panic occurred during boot sequence with the server which carries 256GMB physical memory.

  Unable to handle kernel paging request at ffff814858890c98 RIP:
   [<ffffffff880b73fe>] :megaraid_sas:megasas_complete_cmd_dpc+0x5b/0x39e
  PGD 6fd063 PUD 0
  Oops: 0000 [1] SMP
  last sysfs file: /class/net/eth0/broadcast
  CPU 0
  Modules
  linked in: lockd sunrpc cpufreq_ondemand acpi_cpufreq freq_table
  dm_multipath scsi_dh dm_mod video hwmon backlight sbs i2c_ec button
  battery asus_acpi acpi_memhotplug ac parport_pc lp parport st sg igb(U)
  ide_cd i2c_i801 e1000e(U) i2c_core cdrom pcspkr serio_raw dca
  aic79xx(U) ata_piix libata shpchp megaraid_sas(U) sd_mod scsi_mod ext3
  jbd uhci_hcd ohci_hcd ehci_hcd
  Pid: 0, comm: swapper Tainted: G      2.6.18-164.el5 #1
  RIP: 0010:[<ffffffff880b73fe>]  [<ffffffff880b73fe>] :megaraid_sas:megasas_complete_cmd_dpc+0x5b/0x39e
  RSP: 0018:ffffffff8043bed0  EFLAGS: 00010097
  RAX: ffff81407e29e000 RBX: ffff81407dc57a30 RCX: ffffffff803f1e98
  RDX: 00000000fb4be593 RSI: ffffffff803e3480 RDI: ffff81407dc57968
  RBP: 0000000000000001 R08: ffffffff803f0000 R09: 0000000000000030
  R10: ffff81407fcf4158 R11: ffff81407dc61928 R12: 0000000000000000
  R13: ffff81407dc574f8 R14: 00000000000000ba R15: 00000000000000bb
  FS:  0000000000000000(0000) GS:ffffffff803c0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
  CR2: ffff814858890c98 CR3: 0000004075e03000 CR4: 00000000000006e0
  Process swapper (pid: 0, threadinfo ffffffff803f0000, task ffffffff802ffae0)
  Stack:  0000000000000000 ffff81407dc57968 0000000000000246 ffff81407dc57a30
   0000000000000001 0000000000000000 000000000000000a 0000000000000000
   0000000000000000 ffffffff80093ebb 0000000000000046 0000000000000001
  Call Trace:
   <IRQ>  [<ffffffff80093ebb>] tasklet_action+0x89/0xfd
   [<ffffffff8001235a>] __do_softirq+0x89/0x133
   [<ffffffff8005e2fc>] call_softirq+0x1c/0x28
   [<ffffffff8006cb14>] do_softirq+0x2c/0x85
   [<ffffffff8006c99c>] do_IRQ+0xec/0xf5
   [<ffffffff8019741b>] acpi_processor_idle+0x0/0x463
   [<ffffffff8005d615>] ret_from_intr+0x0/0xa
   <EOI>  [<ffffffff801975ce>] acpi_processor_idle+0x1b3/0x463
   [<ffffffff8019752e>] acpi_processor_idle+0x113/0x463
   [<ffffffff8019741b>] acpi_processor_idle+0x0/0x463
   [<ffffffff8019741b>] acpi_processor_idle+0x0/0x463
   [<ffffffff8004939e>] cpu_idle+0x95/0xb8
   [<ffffffff803fb7fd>] start_kernel+0x220/0x225
   [<ffffffff803fb22f>] _sinittext+0x22f/0x236
  
  Code: 48 8b 2c d0 48 8b 5d 00 8a 13 8d 42 ff 3c 07 0f 87 aa 02 00
  RIP  [<ffffffff880b73fe>] :megaraid_sas:megasas_complete_cmd_dpc+0x5b/0x39e
   RSP <ffffffff8043bed0>