WSL2-Linux-Kernel/Documentation/kdump/kdump.txt

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================================================================
Documentation for Kdump - The kexec-based Crash Dumping Solution
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
================================================================
This document includes overview, setup and installation, and analysis
information.
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
Overview
========
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
Kdump uses kexec to quickly boot to a dump-capture kernel whenever a
dump of the system kernel's memory needs to be taken (for example, when
the system panics). The system kernel's memory image is preserved across
the reboot and is accessible to the dump-capture kernel.
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
You can use common commands, such as cp and scp, to copy the
memory image to a dump file on the local disk, or across the network to
a remote system.
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
Kdump and kexec are currently supported on the x86, x86_64, ppc64, ia64,
s390x and arm architectures.
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
When the system kernel boots, it reserves a small section of memory for
the dump-capture kernel. This ensures that ongoing Direct Memory Access
(DMA) from the system kernel does not corrupt the dump-capture kernel.
The kexec -p command loads the dump-capture kernel into this reserved
memory.
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
On x86 machines, the first 640 KB of physical memory is needed to boot,
regardless of where the kernel loads. Therefore, kexec backs up this
region just before rebooting into the dump-capture kernel.
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
Similarly on PPC64 machines first 32KB of physical memory is needed for
booting regardless of where the kernel is loaded and to support 64K page
size kexec backs up the first 64KB memory.
For s390x, when kdump is triggered, the crashkernel region is exchanged
with the region [0, crashkernel region size] and then the kdump kernel
runs in [0, crashkernel region size]. Therefore no relocatable kernel is
needed for s390x.
All of the necessary information about the system kernel's core image is
encoded in the ELF format, and stored in a reserved area of memory
before a crash. The physical address of the start of the ELF header is
passed to the dump-capture kernel through the elfcorehdr= boot
parameter. Optionally the size of the ELF header can also be passed
when using the elfcorehdr=[size[KMG]@]offset[KMG] syntax.
With the dump-capture kernel, you can access the memory image through
/proc/vmcore. This exports the dump as an ELF-format file that you can
write out using file copy commands such as cp or scp. Further, you can
use analysis tools such as the GNU Debugger (GDB) and the Crash tool to
debug the dump file. This method ensures that the dump pages are correctly
ordered.
Setup and Installation
======================
Install kexec-tools
-------------------
1) Login as the root user.
2) Download the kexec-tools user-space package from the following URL:
http://kernel.org/pub/linux/utils/kernel/kexec/kexec-tools.tar.gz
This is a symlink to the latest version.
The latest kexec-tools git tree is available at:
git://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
and
http://www.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
There is also a gitweb interface available at
http://www.kernel.org/git/?p=utils/kernel/kexec/kexec-tools.git
More information about kexec-tools can be found at
http://horms.net/projects/kexec/
3) Unpack the tarball with the tar command, as follows:
tar xvpzf kexec-tools.tar.gz
4) Change to the kexec-tools directory, as follows:
cd kexec-tools-VERSION
5) Configure the package, as follows:
./configure
6) Compile the package, as follows:
make
7) Install the package, as follows:
make install
Build the system and dump-capture kernels
-----------------------------------------
There are two possible methods of using Kdump.
1) Build a separate custom dump-capture kernel for capturing the
kernel core dump.
2) Or use the system kernel binary itself as dump-capture kernel and there is
no need to build a separate dump-capture kernel. This is possible
only with the architectures which support a relocatable kernel. As
of today, i386, x86_64, ppc64, ia64 and arm architectures support relocatable
kernel.
Building a relocatable kernel is advantageous from the point of view that
one does not have to build a second kernel for capturing the dump. But
at the same time one might want to build a custom dump capture kernel
suitable to his needs.
Following are the configuration setting required for system and
dump-capture kernels for enabling kdump support.
System kernel config options
----------------------------
1) Enable "kexec system call" in "Processor type and features."
CONFIG_KEXEC=y
2) Enable "sysfs file system support" in "Filesystem" -> "Pseudo
filesystems." This is usually enabled by default.
CONFIG_SYSFS=y
Note that "sysfs file system support" might not appear in the "Pseudo
filesystems" menu if "Configure standard kernel features (for small
systems)" is not enabled in "General Setup." In this case, check the
.config file itself to ensure that sysfs is turned on, as follows:
grep 'CONFIG_SYSFS' .config
3) Enable "Compile the kernel with debug info" in "Kernel hacking."
CONFIG_DEBUG_INFO=Y
This causes the kernel to be built with debug symbols. The dump
analysis tools require a vmlinux with debug symbols in order to read
and analyze a dump file.
Dump-capture kernel config options (Arch Independent)
-----------------------------------------------------
1) Enable "kernel crash dumps" support under "Processor type and
features":
CONFIG_CRASH_DUMP=y
2) Enable "/proc/vmcore support" under "Filesystems" -> "Pseudo filesystems".
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
CONFIG_PROC_VMCORE=y
(CONFIG_PROC_VMCORE is set by default when CONFIG_CRASH_DUMP is selected.)
Dump-capture kernel config options (Arch Dependent, i386 and x86_64)
--------------------------------------------------------------------
1) On i386, enable high memory support under "Processor type and
features":
CONFIG_HIGHMEM64G=y
or
CONFIG_HIGHMEM4G
2) On i386 and x86_64, disable symmetric multi-processing support
under "Processor type and features":
CONFIG_SMP=n
(If CONFIG_SMP=y, then specify maxcpus=1 on the kernel command line
when loading the dump-capture kernel, see section "Load the Dump-capture
Kernel".)
3) If one wants to build and use a relocatable kernel,
Enable "Build a relocatable kernel" support under "Processor type and
features"
CONFIG_RELOCATABLE=y
4) Use a suitable value for "Physical address where the kernel is
loaded" (under "Processor type and features"). This only appears when
"kernel crash dumps" is enabled. A suitable value depends upon
whether kernel is relocatable or not.
If you are using a relocatable kernel use CONFIG_PHYSICAL_START=0x100000
This will compile the kernel for physical address 1MB, but given the fact
kernel is relocatable, it can be run from any physical address hence
kexec boot loader will load it in memory region reserved for dump-capture
kernel.
Otherwise it should be the start of memory region reserved for
second kernel using boot parameter "crashkernel=Y@X". Here X is
start of memory region reserved for dump-capture kernel.
Generally X is 16MB (0x1000000). So you can set
CONFIG_PHYSICAL_START=0x1000000
5) Make and install the kernel and its modules. DO NOT add this kernel
to the boot loader configuration files.
Dump-capture kernel config options (Arch Dependent, ppc64)
----------------------------------------------------------
1) Enable "Build a kdump crash kernel" support under "Kernel" options:
CONFIG_CRASH_DUMP=y
2) Enable "Build a relocatable kernel" support
CONFIG_RELOCATABLE=y
Make and install the kernel and its modules.
Dump-capture kernel config options (Arch Dependent, ia64)
----------------------------------------------------------
- No specific options are required to create a dump-capture kernel
for ia64, other than those specified in the arch independent section
above. This means that it is possible to use the system kernel
as a dump-capture kernel if desired.
The crashkernel region can be automatically placed by the system
kernel at run time. This is done by specifying the base address as 0,
or omitting it all together.
crashkernel=256M@0
or
crashkernel=256M
If the start address is specified, note that the start address of the
kernel will be aligned to 64Mb, so if the start address is not then
any space below the alignment point will be wasted.
Dump-capture kernel config options (Arch Dependent, arm)
----------------------------------------------------------
- To use a relocatable kernel,
Enable "AUTO_ZRELADDR" support under "Boot" options:
AUTO_ZRELADDR=y
Extended crashkernel syntax
===========================
While the "crashkernel=size[@offset]" syntax is sufficient for most
configurations, sometimes it's handy to have the reserved memory dependent
on the value of System RAM -- that's mostly for distributors that pre-setup
the kernel command line to avoid a unbootable system after some memory has
been removed from the machine.
The syntax is:
crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
range=start-[end]
For example:
crashkernel=512M-2G:64M,2G-:128M
This would mean:
1) if the RAM is smaller than 512M, then don't reserve anything
(this is the "rescue" case)
2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
3) if the RAM size is larger than 2G, then reserve 128M
Boot into System Kernel
=======================
1) Update the boot loader (such as grub, yaboot, or lilo) configuration
files as necessary.
2) Boot the system kernel with the boot parameter "crashkernel=Y@X",
where Y specifies how much memory to reserve for the dump-capture kernel
and X specifies the beginning of this reserved memory. For example,
"crashkernel=64M@16M" tells the system kernel to reserve 64 MB of memory
starting at physical address 0x01000000 (16MB) for the dump-capture kernel.
On x86 and x86_64, use "crashkernel=64M@16M".
On ppc64, use "crashkernel=128M@32M".
On ia64, 256M@256M is a generous value that typically works.
The region may be automatically placed on ia64, see the
dump-capture kernel config option notes above.
Add size restriction to the kdump documentation In efi_init() memory aligns in IA64_GRANULE_SIZE(16M). If set "crashkernel=1024M-:600M" and use sparse memory model, when crash kernel booting it changes [128M-728M] to [128M-720M]. But initrd memory is in [709M-727M], and virt_addr_valid() *can not* check the invalid pages when freeing initrd memory, because there are some pages missed at the end of the section, and this causes error. ... Unpacking initramfs... Freeing initrd memory: 19648kB freed BUG: Bad page state in process swapper pfn:02d00 page:e0000000102dd800 flags:(null) count:0 mapcount:1 mapping:(null) index:0 Call Trace: [<a000000100018dc0>] show_stack+0x80/0xa0 sp=e000000021e8fbd0 bsp=e000000021e81360 [<a00000010090fcc0>] dump_stack+0x30/0x50 sp=e000000021e8fda0 bsp=e000000021e81348 [<a0000001001a3180>] bad_page+0x280/0x380 sp=e000000021e8fda0 bsp=e000000021e81308 [<a0000001001a8740>] free_hot_cold_page+0x3a0/0x5c0 sp=e000000021e8fda0 bsp=e000000021e812a0 [<a0000001001a8a50>] free_hot_page+0x30/0x60 sp=e000000021e8fda0 bsp=e000000021e81280 [<a0000001001a8b30>] __free_pages+0xb0/0xe0 sp=e000000021e8fda0 bsp=e000000021e81258 [<a0000001001a8c00>] free_pages+0xa0/0xc0 sp=e000000021e8fda0 bsp=e000000021e81230 [<a000000100bb40c0>] free_initrd_mem+0x230/0x290 sp=e000000021e8fda0 bsp=e000000021e811d8 [<a000000100ba6620>] populate_rootfs+0x1c0/0x280 sp=e000000021e8fdb0 bsp=e000000021e811a0 [<a00000010000ac30>] do_one_initcall+0x3b0/0x3e0 sp=e000000021e8fdb0 bsp=e000000021e81158 [<a000000100ba0a90>] kernel_init+0x3f0/0x4b0 sp=e000000021e8fdb0 bsp=e000000021e81108 [<a000000100016890>] kernel_thread_helper+0xd0/0x100 sp=e000000021e8fe30 bsp=e000000021e810e0 [<a00000010000a4c0>] start_kernel_thread+0x20/0x40 sp=e000000021e8fe30 bsp=e000000021e810e0 ... In "http://marc.info/?l=linux-arch&m=136147092429314&w=2" Tony said: "Perhaps in Documentation/kdump/kdump.txt (which the crashkernel entry in kernel-parameters.txt points at). The ia64 section of kdump.txt notes that the start address will be rounded up to a GRANULE boundary, but doesn't talk about restrictions on the size." This patch add size restriction to the documentation of kdump. Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2013-03-25 15:14:16 +04:00
If use sparse memory, the size should be rounded to GRANULE boundaries.
On s390x, typically use "crashkernel=xxM". The value of xx is dependent
on the memory consumption of the kdump system. In general this is not
dependent on the memory size of the production system.
On arm, the use of "crashkernel=Y@X" is no longer necessary; the
kernel will automatically locate the crash kernel image within the
first 512MB of RAM if X is not given.
Load the Dump-capture Kernel
============================
After booting to the system kernel, dump-capture kernel needs to be
loaded.
Based on the architecture and type of image (relocatable or not), one
can choose to load the uncompressed vmlinux or compressed bzImage/vmlinuz
of dump-capture kernel. Following is the summary.
For i386 and x86_64:
- Use vmlinux if kernel is not relocatable.
- Use bzImage/vmlinuz if kernel is relocatable.
For ppc64:
- Use vmlinux
For ia64:
- Use vmlinux or vmlinuz.gz
For s390x:
- Use image or bzImage
For arm:
- Use zImage
If you are using a uncompressed vmlinux image then use following command
to load dump-capture kernel.
kexec -p <dump-capture-kernel-vmlinux-image> \
--initrd=<initrd-for-dump-capture-kernel> --args-linux \
--append="root=<root-dev> <arch-specific-options>"
If you are using a compressed bzImage/vmlinuz, then use following command
to load dump-capture kernel.
kexec -p <dump-capture-kernel-bzImage> \
--initrd=<initrd-for-dump-capture-kernel> \
--append="root=<root-dev> <arch-specific-options>"
If you are using a compressed zImage, then use following command
to load dump-capture kernel.
kexec --type zImage -p <dump-capture-kernel-bzImage> \
--initrd=<initrd-for-dump-capture-kernel> \
--dtb=<dtb-for-dump-capture-kernel> \
--append="root=<root-dev> <arch-specific-options>"
Please note, that --args-linux does not need to be specified for ia64.
It is planned to make this a no-op on that architecture, but for now
it should be omitted
Following are the arch specific command line options to be used while
loading dump-capture kernel.
For i386, x86_64 and ia64:
"1 irqpoll maxcpus=1 reset_devices"
For ppc64:
"1 maxcpus=1 noirqdistrib reset_devices"
For s390x:
"1 maxcpus=1 cgroup_disable=memory"
For arm:
"1 maxcpus=1 reset_devices"
Notes on loading the dump-capture kernel:
* By default, the ELF headers are stored in ELF64 format to support
systems with more than 4GB memory. On i386, kexec automatically checks if
the physical RAM size exceeds the 4 GB limit and if not, uses ELF32.
So, on non-PAE systems, ELF32 is always used.
The --elf32-core-headers option can be used to force the generation of ELF32
headers. This is necessary because GDB currently cannot open vmcore files
with ELF64 headers on 32-bit systems.
* The "irqpoll" boot parameter reduces driver initialization failures
due to shared interrupts in the dump-capture kernel.
* You must specify <root-dev> in the format corresponding to the root
device name in the output of mount command.
* Boot parameter "1" boots the dump-capture kernel into single-user
mode without networking. If you want networking, use "3".
* We generally don' have to bring up a SMP kernel just to capture the
dump. Hence generally it is useful either to build a UP dump-capture
kernel or specify maxcpus=1 option while loading dump-capture kernel.
Note, though maxcpus always works, you had better replace it with
nr_cpus to save memory if supported by the current ARCH, such as x86.
* For s390x there are two kdump modes: If a ELF header is specified with
the elfcorehdr= kernel parameter, it is used by the kdump kernel as it
is done on all other architectures. If no elfcorehdr= kernel parameter is
specified, the s390x kdump kernel dynamically creates the header. The
second mode has the advantage that for CPU and memory hotplug, kdump has
not to be reloaded with kexec_load().
* For s390x systems with many attached devices the "cio_ignore" kernel
parameter should be used for the kdump kernel in order to prevent allocation
of kernel memory for devices that are not relevant for kdump. The same
applies to systems that use SCSI/FCP devices. In that case the
"allow_lun_scan" zfcp module parameter should be set to zero before
setting FCP devices online.
Kernel Panic
============
After successfully loading the dump-capture kernel as previously
described, the system will reboot into the dump-capture kernel if a
system crash is triggered. Trigger points are located in panic(),
die(), die_nmi() and in the sysrq handler (ALT-SysRq-c).
The following conditions will execute a crash trigger point:
If a hard lockup is detected and "NMI watchdog" is configured, the system
will boot into the dump-capture kernel ( die_nmi() ).
If die() is called, and it happens to be a thread with pid 0 or 1, or die()
is called inside interrupt context or die() is called and panic_on_oops is set,
the system will boot into the dump-capture kernel.
On powerpc systems when a soft-reset is generated, die() is called by all cpus
and the system will boot into the dump-capture kernel.
For testing purposes, you can trigger a crash by using "ALT-SysRq-c",
"echo c > /proc/sysrq-trigger" or write a module to force the panic.
Write Out the Dump File
=======================
After the dump-capture kernel is booted, write out the dump file with
the following command:
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
cp /proc/vmcore <dump-file>
Analysis
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
========
Before analyzing the dump image, you should reboot into a stable kernel.
You can do limited analysis using GDB on the dump file copied out of
/proc/vmcore. Use the debug vmlinux built with -g and run the following
command:
gdb vmlinux <dump-file>
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
Stack trace for the task on processor 0, register display, and memory
display work fine.
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
Note: GDB cannot analyze core files generated in ELF64 format for x86.
On systems with a maximum of 4GB of memory, you can generate
ELF32-format headers using the --elf32-core-headers kernel option on the
dump kernel.
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
You can also use the Crash utility to analyze dump files in Kdump
format. Crash is available on Dave Anderson's site at the following URL:
http://people.redhat.com/~anderson/
kernel: add panic_on_warn There have been several times where I have had to rebuild a kernel to cause a panic when hitting a WARN() in the code in order to get a crash dump from a system. Sometimes this is easy to do, other times (such as in the case of a remote admin) it is not trivial to send new images to the user. A much easier method would be a switch to change the WARN() over to a panic. This makes debugging easier in that I can now test the actual image the WARN() was seen on and I do not have to engage in remote debugging. This patch adds a panic_on_warn kernel parameter and /proc/sys/kernel/panic_on_warn calls panic() in the warn_slowpath_common() path. The function will still print out the location of the warning. An example of the panic_on_warn output: The first line below is from the WARN_ON() to output the WARN_ON()'s location. After that the panic() output is displayed. WARNING: CPU: 30 PID: 11698 at /home/prarit/dummy_module/dummy-module.c:25 init_dummy+0x1f/0x30 [dummy_module]() Kernel panic - not syncing: panic_on_warn set ... CPU: 30 PID: 11698 Comm: insmod Tainted: G W OE 3.17.0+ #57 Hardware name: Intel Corporation S2600CP/S2600CP, BIOS RMLSDP.86I.00.29.D696.1311111329 11/11/2013 0000000000000000 000000008e3f87df ffff88080f093c38 ffffffff81665190 0000000000000000 ffffffff818aea3d ffff88080f093cb8 ffffffff8165e2ec ffffffff00000008 ffff88080f093cc8 ffff88080f093c68 000000008e3f87df Call Trace: [<ffffffff81665190>] dump_stack+0x46/0x58 [<ffffffff8165e2ec>] panic+0xd0/0x204 [<ffffffffa038e05f>] ? init_dummy+0x1f/0x30 [dummy_module] [<ffffffff81076b90>] warn_slowpath_common+0xd0/0xd0 [<ffffffffa038e040>] ? dummy_greetings+0x40/0x40 [dummy_module] [<ffffffff81076c8a>] warn_slowpath_null+0x1a/0x20 [<ffffffffa038e05f>] init_dummy+0x1f/0x30 [dummy_module] [<ffffffff81002144>] do_one_initcall+0xd4/0x210 [<ffffffff811b52c2>] ? __vunmap+0xc2/0x110 [<ffffffff810f8889>] load_module+0x16a9/0x1b30 [<ffffffff810f3d30>] ? store_uevent+0x70/0x70 [<ffffffff810f49b9>] ? copy_module_from_fd.isra.44+0x129/0x180 [<ffffffff810f8ec6>] SyS_finit_module+0xa6/0xd0 [<ffffffff8166cf29>] system_call_fastpath+0x12/0x17 Successfully tested by me. hpa said: There is another very valid use for this: many operators would rather a machine shuts down than being potentially compromised either functionally or security-wise. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Fabian Frederick <fabf@skynet.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-11 02:45:50 +03:00
Trigger Kdump on WARN()
=======================
The kernel parameter, panic_on_warn, calls panic() in all WARN() paths. This
will cause a kdump to occur at the panic() call. In cases where a user wants
to specify this during runtime, /proc/sys/kernel/panic_on_warn can be set to 1
to achieve the same behaviour.
Contact
[PATCH] kdump: Documentation for Kdump This patch contains the documentation for the kexec based crash dump tool. Quick kdump-howto ================================================================ 1) Download and build kexec-tools. 2) Download and build the latest kexec/kdump (-mm) kernel patchset. Two kernels need to be built in order to get this feature working. A) First kernel: a) Enable "kexec system call" feature: CONFIG_KEXEC=y b) Physical load address (use default): CONFIG_PHYSICAL_START=0x100000 c) Enable "sysfs file system support": CONFIG_SYSFS=y d) Boot into first kernel with the command line parameter "crashkernel=Y@X": For example: "crashkernel=64M@16M". B) Second kernel: a) Enable "kernel crash dumps" feature: CONFIG_CRASH_DUMP=y b) Physical load addreess, use same load address as X in "crashkernel" kernel parameter in d) above, e.g., 16 MB or 0x1000000. CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y 3) Boot into the first kernel. 4) Load the second kernel to be booted using: kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev> maxcpus=1 init 1" 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic, for testing purposes. 6) See Documentation/kdump.txt for how to read the first kernel's memory image and how to analyze it. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: randy_dunlap <rdunlap@xenotime.net> Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-26 01:58:15 +04:00
=======
Vivek Goyal (vgoyal@redhat.com)
Maneesh Soni (maneesh@in.ibm.com)