diff options
Diffstat (limited to 'Documentation/kdump/kdump.txt')
| -rw-r--r-- | Documentation/kdump/kdump.txt | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt index b0f412e4279..7ff213f4bec 100644 --- a/Documentation/kdump/kdump.txt +++ b/Documentation/kdump/kdump.txt @@ -66,12 +66,18 @@ SETUP CONFIG_PHYSICAL_START=0x1000000 c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y - - Note: Options a) and b) depend upon "Configure standard kernel features - (for small systems)" (under General setup). - Option a) also depends on CONFIG_HIGHMEM (under Processor + d) Disable SMP support and build a UP kernel (Until it is fixed). + CONFIG_SMP=n + e) Enable "Local APIC support on uniprocessors". + CONFIG_X86_UP_APIC=y + f) Enable "IO-APIC support on uniprocessors" + CONFIG_X86_UP_IOAPIC=y + + Note: i) Options a) and b) depend upon "Configure standard kernel features + (for small systems)" (under General setup). + ii) Option a) also depends on CONFIG_HIGHMEM (under Processor type and features). - Both option a) and b) are under "Processor type and features". + iii) Both option a) and b) are under "Processor type and features". 3) Boot into the first kernel. You are now ready to try out kexec-based crash dumps. @@ -79,7 +85,7 @@ SETUP 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" + init 1 irqpoll" Note: i) <second-kernel> has to be a vmlinux image. bzImage will not work, as of now. @@ -87,12 +93,12 @@ SETUP is sufficient to represent the physical memory up to 4GB. To store headers in ELF64 format, specifiy "--elf64-core-headers" on the kexec command line additionally. - iii) For now (or until it is fixed), it's best to build the - second-kernel without multi-processor support, i.e., make it - a uniprocessor kernel. + iii) Specify "irqpoll" as command line parameter. This reduces driver + initialization failures in second kernel due to shared interrupts. 5) System reboots into the second kernel when a panic occurs. A module can be - written to force the panic, for testing purposes. + written to force the panic or "ALT-SysRq-c" can be used initiate a crash + dump for testing purposes. 6) Write out the dump file using @@ -131,5 +137,5 @@ TODO CONTACT ======= -Hariprasad Nellitheertha - hari at in dot ibm dot com Vivek Goyal (vgoyal@in.ibm.com) +Maneesh Soni (maneesh@in.ibm.com) |