[PATCH] i386/x86-64: Improve Kconfig description of CRASH_DUMP

Improve Kconfig description of CONFIG_CRASH_DUMP. Previously
it was too brief to be useful.

Cc: vgoyal@in.ibm.com
Cc: ebiederm@xmission.com

Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 8 insertions, 1 deletions

diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 6cd4878625f1..927b392a4aa0 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -488,7 +488,14 @@ config CRASH_DUMP
         bool "kernel crash dumps (EXPERIMENTAL)"
         depends on EXPERIMENTAL
         help
-                Generate crash dump after being started by kexec.
+          Generate crash dump after being started by kexec.
+          This should be normally only set in special crash dump kernels
+          which are loaded in the main kernel with kexec-tools into
+          a specially reserved region and then later executed after
+          a crash by kdump/kexec. The crash dump kernel must be compiled
+          to a memory address not used by the main kernel or BIOS using
+          PHYSICAL_START.
+          For more details see Documentation/kdump/kdump.txt
 
 config PHYSICAL_START
         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)