Description of problem:
Kdump kernel hangs on ibm-x3620m3-01.rhts.eng.bos.redhat.com:

SysRq : Trigger a crashdump
Linux version 2.6.18-273.el5 (mockbuild.bos.redhat.com) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-51)) #1 SMP Mon Jul 4 14:12:24 EDT 2011
Command line: ro root=/dev/VolGroup00/LogVol00 console=ttyS0,115200 irqpoll maxcpus=1 reset_devices  memmap=exactmap memmap=561K@64K memmap=6096K@16384K memmap=124399K@23041K elfcorehdr=147440K memmap=15K$625K memmap=33616K$2014876K memmap=704K$2057140K memmap=320K$2087484K memmap=1024K#2087804K memmap=128K#2088828K memmap=270336K$2088960K memmap=16384K$4128768K memmap=16K$4174960K memmap=8192K$4186112K
BIOS-provided physical RAM map:
 BIOS-e820: 0000000000010000 - 000000000009c400 (usable)
 BIOS-e820: 000000000009c400 - 00000000000a0000 (reserved)
 BIOS-e820: 0000000000100000 - 000000007afa7000 (usable)
 BIOS-e820: 000000007afa7000 - 000000007d07b000 (reserved)
 BIOS-e820: 000000007d07b000 - 000000007d8ed000 (usable)
 BIOS-e820: 000000007d8ed000 - 000000007d99d000 (reserved)
 BIOS-e820: 000000007d99d000 - 000000007f68f000 (usable)
 BIOS-e820: 000000007f68f000 - 000000007f6df000 (reserved)
 BIOS-e820: 000000007f6df000 - 000000007f7df000 (ACPI NVS)
 BIOS-e820: 000000007f7df000 - 000000007f7ff000 (ACPI data)
 BIOS-e820: 000000007f7ff000 - 000000007f800000 (usable)
 BIOS-e820: 000000007f800000 - 0000000090000000 (reserved)
 BIOS-e820: 00000000fc000000 - 00000000fd000000 (reserved)
 BIOS-e820: 00000000fed1c000 - 00000000fed20000 (reserved)
 BIOS-e820: 00000000ff800000 - 0000000100000000 (reserved)
user-defined physical RAM map:
 user: 0000000000010000 - 000000000009c400 (usable)
 user: 000000000009c400 - 00000000000a0000 (reserved)
 user: 0000000001000000 - 00000000015f4000 (usable)
 user: 0000000001680400 - 0000000008ffc000 (usable)
 user: 000000007afa7000 - 000000007d07b000 (reserved)
 user: 000000007d8ed000 - 000000007d99d000 (reserved)
 user: 000000007f68f000 - 000000007f6df000 (reserved)
 user: 000000007f6df000 - 000000007f7ff000 (ACPI data)
 user: 000000007f800000 - 0000000090000000 (reserved)
 user: 00000000fc000000 - 00000000fd000000 (reserved)
 user: 00000000fed1c000 - 00000000fed20000 (reserved)
 user: 00000000ff800000 - 0000000100000000 (reserved)
DMI 2.5 present.
No NUMA configuration found
Faking a node at 0000000000000000-0000000008ffc000
Bootmem setup node 0 0000000000000000-0000000008ffc000
Memory for crash kernel (0x0 to 0x0) notwithin permissible range
disabling kdump
ACPI: PM-Timer IO Port: 0x588
ACPI: LAPIC (acpi_id[0x00] lapic_id[0x00] disabled)
ACPI: LAPIC (acpi_id[0x01] lapic_id[0x02] disabled)
ACPI: LAPIC (acpi_id[0x02] lapic_id[0x04] disabled)
ACPI: LAPIC (acpi_id[0x03] lapic_id[0x10] disabled)
ACPI: LAPIC (acpi_id[0x04] lapic_id[0x12] disabled)
ACPI: LAPIC (acpi_id[0x05] lapic_id[0x14] disabled)
ACPI: LAPIC (acpi_id[0x06] lapic_id[0x20] enabled)
Processor #32 6:12 APIC version 21
ACPI: LAPIC (acpi_id[0x07] lapic_id[0x22] enabled)
Processor #34 6:12 APIC version 21
ACPI: LAPIC (acpi_id[0x08] lapic_id[0x24] disabled)
ACPI: LAPIC (acpi_id[0x09] lapic_id[0x30] disabled)
ACPI: LAPIC (acpi_id[0x0a] lapic_id[0x32] enabled)
Processor #50 6:12 APIC version 21
ACPI: LAPIC (acpi_id[0x0b] lapic_id[0x34] enabled)
Processor #52 6:12 APIC version 21
ACPI: LAPIC (acpi_id[0x0c] lapic_id[0x01] disabled)
ACPI: LAPIC (acpi_id[0x0d] lapic_id[0x03] disabled)
ACPI: LAPIC (acpi_id[0x0e] lapic_id[0x05] disabled)
ACPI: LAPIC (acpi_id[0x0f] lapic_id[0x11] disabled)
ACPI: LAPIC (acpi_id[0x10] lapic_id[0x13] disabled)
ACPI: LAPIC (acpi_id[0x11] lapic_id[0x15] disabled)
ACPI: LAPIC (acpi_id[0x12] lapic_id[0x21] enabled)
Processor #33 6:12 APIC version 21
ACPI: LAPIC (acpi_id[0x13] lapic_id[0x23] enabled)
Processor #35 6:12 APIC version 21
ACPI: LAPIC (acpi_id[0x14] lapic_id[0x25] disabled)
ACPI: LAPIC (acpi_id[0x15] lapic_id[0x31] disabled)
ACPI: LAPIC (acpi_id[0x16] lapic_id[0x33] enabled)
Processor #51 6:12 APIC version 21
ACPI: LAPIC (acpi_id[0x17] lapic_id[0x35] enabled)
Processor #53 6:12 APIC version 21
ACPI: LAPIC_NMI (acpi_id[0xff] dfl dfl lint[0x1])
ACPI: IOAPIC (id[0x08] address[0xfec00000] gsi_base[0])
IOAPIC[0]: apic_id 8, version 32, address 0xfec00000, GSI 0-23
ACPI: IOAPIC (id[0x09] address[0xfec80000] gsi_base[24])
IOAPIC[1]: apic_id 9, version 32, address 0xfec80000, GSI 24-47
ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 dfl dfl)
ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level)
Setting APIC routing to physical flat
ACPI: HPET id: 0x8086a301 base: 0xfed00000
Using ACPI (MADT) for SMP configuration information
Nosave address range: 000000000009c000 - 000000000009d000
Nosave address range: 000000000009d000 - 00000000000a0000
Nosave address range: 00000000000a0000 - 0000000001000000
Nosave address range: 00000000015f4000 - 0000000001681000
Allocating PCI resources starting at 10000000 (gap: 8ffc000:71fab000)
SMP: Allowing 24 CPUs, 16 hotplug CPUs
Built 1 zonelists.  Total pages: 32247
Kernel command line: ro root=/dev/VolGroup00/LogVol00 console=ttyS0,115200 irqpoll maxcpus=1 reset_devices  memmap=exactmap memmap=561K@64K memmap=6096K@16384K memmap=124399K@23041K elfcorehdr=147440K memmap=15K$625K memmap=33616K$2014876K memmap=704K$2057140K memmap=320K$2087484K memmap=1024K#2087804K memmap=128K#2088828K memmap=270336K$2088960K memmap=16384K$4128768K memmap=16K$4174960K memmap=8192K$4186112K
Misrouted IRQ fixup and polling support enabled
This may significantly impact system performance
Initializing CPU#0
PID hash table entries: 512 (order: 9, 4096 bytes)
Console: colour VGA+ 80x25
Dentry cache hash table entries: 16384 (order: 5, 131072 bytes)
Inode-cache hash table entries: 8192 (order: 4, 65536 bytes)
Checking aperture...
Memory: 115484k/147440k available (2603k kernel code, 15568k reserved, 1660k data, 224k init)
Calibrating delay loop (skipped), value calculated using timer frequency.. 4800.31 BogoMIPS (lpj=2400155)
Security Framework v1.0.0 initialized
SELinux:  Initializing.
selinux_register_security:  Registering secondary module capability
Capability LSM initialized as secondary
Mount-cache hash table entries: 256
CPU: L1 I cache: 32K, L1 D cache: 32K
CPU: L2 cache: 256K
CPU: L3 cache: 12288K
using mwait in idle threads.
CPU: Physical Processor ID: 1
CPU: Processor Core ID: 1
MCE: Machine Check Exception Reporting is disabled.
SMP alternatives: switching to UP code
ACPI: Core revision 20060707
Using local APIC timer interrupts.
Detected 8.333 MHz APIC timer.
Brought up 1 CPUs
NMI watchdog testing PASSED.
time.c: Using 14.318180 MHz WALL HPET GTOD HPET/TSC timer.
time.c: Detected 2400.155 MHz processor.
checking if image is initramfs... it is
Freeing initrd memory: 4715k freed
NET: Registered protocol family 16
ACPI: bus type pci registered
PCI: Using MMCONFIG at 80000000
ACPI: Interpreter enabled
ACPI: Using IOAPIC for interrupt routing
ACPI: No dock devices found.
ACPI: PCI Root Bridge [PCI0] (0000:00)
PCI: Transparent bridge - 0000:00:1e.0
ACPI: PCI Interrupt Link [LNKA] (IRQs 3 4 5 6 7 9 10 11 12 14 15) *0, disabled.
ACPI: PCI Interrupt Link [LNKB] (IRQs 3 4 5 6 7 9 10 11 12 14 15) *0, disabled.
ACPI: PCI Interrupt Link [LNKC] (IRQs 3 4 5 6 7 9 10 11 12 14 15) *0, disabled.
ACPI: PCI Interrupt Link [LNKD] (IRQs 3 4 5 6 7 9 10 11 12 14 15) *0, disabled.
ACPI: PCI Interrupt Link [LNKE] (IRQs 3 4 5 6 7 9 10 11 12 14 15) *0, disabled.
ACPI: PCI Interrupt Link [LNKF] (IRQs 3 4 5 6 7 9 10 11 12 14 15) *0, disabled.
ACPI: PCI Interrupt Link [LNKG] (IRQs 3 4 5 6 7 9 10 11 12 14 15) *0, disabled.
ACPI: PCI Interrupt Link [LNKH] (IRQs 3 4 5 6 7 9 10 11 12 14 15) *0, disabled.
Linux Plug and Play Support v0.97 (c) Adam Belay
pnp: PnP ACPI init
pnp: PnP ACPI: found 11 devices
usbcore: registered new driver usbfs
usbcore: registered new driver hub
PCI: Using ACPI for IRQ routing
PCI: If a device doesn't work, try "pci=routeirq".  If it helps, post a report
NetLabel: Initializing
NetLabel:  domain hash size = 128
NetLabel:  protocols = UNLABELED CIPSOv4
NetLabel:  unlabeled traffic allowed by default
hpet0: at MMIO 0xfed00000 (virtual 0xffffffffff5fe000), IRQs 2, 8, 0, 0
hpet0: 4 64-bit timers, 14318180 Hz
DMAR:Host address width 51
DMAR:DRHD base: 0x000000fe710000 flags: 0x1
IOMMU fe710000: ver 1:0 cap c90780106f0462 ecap f020fe
DMAR:RMRR base: 0x0000007d910000 end: 0x0000007d98ffff
DMAR:ATSR flags: 0x0
PCI-GART: No AMD northbridge found.
pnp: 00:05: iomem range 0xfed00000-0xfed003ff has been reserved
pnp: 00:06: ioport range 0x400-0x47f has been reserved
pnp: 00:06: ioport range 0x480-0x49f has been reserved
pnp: 00:07: ioport range 0x3f8-0x3ff has been reserved
pnp: 00:08: iomem range 0xfed1c000-0xfed1ffff could not be reserved
pnp: 00:08: iomem range 0xfec00000-0xfecfffff has been reserved
pnp: 00:08: iomem range 0xfee00000-0xfeefffff has been reserved
pnp: 00:08: iomem range 0x80000000-0x8fffffff could not be reserved
pnp: 00:09: ioport range 0xca0-0xca1 has been reserved
pnp: 00:09: ioport range 0xca4-0xca9 has been reserved
pnp: 00:09: ioport range 0xcaa-0xcab has been reserved
pnp: 00:09: ioport range 0xcac-0xccb has been reserved
pnp: 00:0a: ioport range 0xca2-0xca2 has been reserved
pnp: 00:0a: ioport range 0xca3-0xca3 has been reserved
PCI: Bridge: 0000:00:01.0
  IO window: 2000-2fff
  MEM window: 92a00000-92afffff
  PREFETCH window 0x0000000098000000-0x00000000980fffff
PCI: Bridge: 0000:00:09.0
  IO window: 1000-1fff
  MEM window: 92900000-929fffff
  PREFETCH window 0x0000000098100000-0x00000000981fffff
PCI: Bridge: 0000:00:1c.0
  IO window: disabled.
  MEM window: disabled.
  PREFETCH window: disabled.
PCI: Bridge: 0000:06:00.0
  IO window: disabled.
  MEM window: 92000000-928fffff
  PREFETCH window 0x0000000091000000-0x0000000091ffffff
PCI: Bridge: 0000:00:1c.4
  IO window: disabled.
  MEM window: 92000000-928fffff
  PREFETCH window 0x0000000091000000-0x0000000091ffffff
PCI: Bridge: 0000:00:1e.0
  IO window: disabled.
  MEM window: disabled.
  PREFETCH window: disabled.
GSI 16 sharing vector 0xA9 and IRQ 16
ACPI: PCI Interrupt 0000:00:01.0[A] -> GSI 28 (level, low) -> IRQ 169
GSI 17 sharing vector 0xB1 and IRQ 17
ACPI: PCI Interrupt 0000:00:09.0[A] -> GSI 32 (level, low) -> IRQ 177
GSI 18 sharing vector 0xB9 and IRQ 18
ACPI: PCI Interrupt 0000:00:1c.0[A] -> GSI 16 (level, low) -> IRQ 185
ACPI: PCI Interrupt 0000:00:1c.4[A] -> GSI 16 (level, low) -> IRQ 185
ACPI: PCI Interrupt 0000:06:00.0[A] -> GSI 16 (level, low) -> IRQ 185
NET: Registered protocol family 2
IP route cache hash table entries: 1024 (order: 1, 8192 bytes)
TCP established hash table entries: 4096 (order: 4, 65536 bytes)
TCP bind hash table entries: 2048 (order: 3, 32768 bytes)
TCP: Hash tables configured (established 4096 bind 2048)
TCP reno registered
audit: initializing netlink socket (disabled)
type=2000 audit(1310600501.531:1): initialized
Total HugeTLB memory allocated, 0
VFS: Disk quotas dquot_6.5.1
Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
Initializing Cryptographic API
alg: No test for crc32c (crc32c-generic)
ksign: Installing public key data
Loading keyring
- Added public key B48F8D2FABD39848
- User ID: Red Hat, Inc. (Kernel Module GPG key)
io scheduler noop registered
io scheduler anticipatory registered
io scheduler deadline registered
io scheduler cfq registered (default)
pci_hotplug: PCI Hot Plug PCI Core version: 0.5
BIOS reported wrong ACPI idfor the processor
ACPI Exception (evxface-0545): AE_NOT_EXIST, Removing notify handler [20060707]
Real Time Clock Driver v1.12ac
Non-volatile memory driver v1.2
Linux agpgart interface v0.101 (c) Dave Jones
Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled
�serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
brd: module loaded
Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
ide-floppy driver 0.99.newide
usbcore: registered new driver hiddev
usbcore: registered new driver usbhid
drivers/usb/input/hid-core.c: v2.6:USB HID core driver
PNP: No PS/2 controller found. Probing ports directly.
serio: i8042 KBD port at 0x60,0x64 irq 1
serio: i8042 AUX port at 0x60,0x64 irq 12
mice: PS/2 mouse device common for all mice
md: md driver 0.90.3 MAX_MD_DEVS=256, MD_SB_DISKS=27
md: bitmap version 4.39
TCP bic registered
Initializing IPsec netlink socket
NET: Registered protocol family 1
NET: Registered protocol family 17
ACPI: (supports S0 S1 S5)
Initalizing network drop monitor service
Freeing unused kernel memory: 224k freed
Write protecting the kernel read-only data: 527k
Mounting proc filesystem
Mounting sysfs filesystem
Creating /dev
Creating initial device nodes
Loading scsi_mod.ko module
SCSI subsystem initialized
Loading sd_mod.ko module
Loading megaraid_sas.ko module
megasas: 00.00.05.38-rh1 Tue. May. 3 17:00:00 PDT 2011
megaraid_sas 0000:10:00.0: resetting MSI-X
megasas: 0x1000:0x0073:0x1014:0x03b1: bus 16:slot 0:func 0
ACPI: PCI Interrupt 0000:10:00.0[A] -> GSI 32 (level, low) -> IRQ 177
megasas: Waiting for FW to come to ready state
megasas: FW now in Ready state
megasas: Failed to init firmware
ACPI: PCI interrupt for device 0000:10:00.0 disabled
Loading libata.ko module
Loading ahci.ko module
ACPI: PCI Interrupt 0000:00:1f.2[A] -> GSI 16 (level, low) -> IRQ 185
ahci 0000:00:1f.2: AHCI 0001.0200 32 slots 6 ports 3 Gbps 0x3f impl SATA mode
ahci 0000:00:1f.2: flags: 64bit ncq sntf pm led clo pio slum part ems
scsi1 : ahci
scsi2 : ahci
scsi3 : ahci
scsi4 : ahci
scsi5 : ahci
scsi6 : ahci
ata1: SATA max UDMA/133 abar m2048@0x92b20000 port 0x92b20100 irq 50
ata2: SATA max UDMA/133 abar m2048@0x92b20000 port 0x92b20180 irq 50
ata3: SATA max UDMA/133 abar m2048@0x92b20000 port 0x92b20200 irq 50
ata4: SATA max UDMA/133 abar m2048@0x92b20000 port 0x92b20280 irq 50
ata5: SATA max UDMA/133 abar m2048@0x92b20000 port 0x92b20300 irq 50
ata6: SATA max UDMA/133 abar m2048@0x92b20000 port 0x92b20380 irq 50
ata1: SATA link down (SStatus 0 SControl 300)
ata2: SATA link down (SStatus 0 SControl 300)
ata3: SATA link down (SStatus 0 SControl 300)
ata4: SATA link down (SStatus 0 SControl 300)
ata5: SATA link down (SStatus 0 SControl 300)
ata6: SATA link down (SStatus 0 SControl 300)
Loading jbd.ko module
Loading ext3.ko module
Loading dm-mod.ko module
device-mapper: uevent: version 1.0.3
device-mapper: ioctl: 4.11.6-ioctl (2011-02-18) initialised: dm-devel
Loading dm-log.ko module
Loading dm-mirror.ko module
Loading dm-zero.ko module
Loading dm-snapshot.ko module
Waiting for required block device discovery
Waiting for sda...
<------------------------- hangs here!


Version-Release number of selected component (if applicable):
kernel 2.6.18-273.el6



How reproducible:
always

Steps to Reproduce:
1. config kdump service on ibm-x3620m3-01.rhts.eng.bos.redhat.com, using local disk as target
2. echo c >/proc/sysrq-trigger
3.
  
Actual results:
capture kernel hangs up

Expected results:
kdump works

Additional info: