[RESEND PATCH v4 5/5] powerpc/fadump: update documentation about crashkernel parameter reuse
Hari Bathini
hbathini at linux.vnet.ibm.com
Fri Mar 24 04:04:39 PDT 2017
As we are reusing crashkernel parameter instead of fadump_reserve_mem
parameter to specify the memory to reserve for fadump's crash kernel,
update the documentation accordingly.
Signed-off-by: Hari Bathini <hbathini at linux.vnet.ibm.com>
---
Documentation/powerpc/firmware-assisted-dump.txt | 23 ++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)
diff --git a/Documentation/powerpc/firmware-assisted-dump.txt b/Documentation/powerpc/firmware-assisted-dump.txt
index 3007bc9..8394bc8 100644
--- a/Documentation/powerpc/firmware-assisted-dump.txt
+++ b/Documentation/powerpc/firmware-assisted-dump.txt
@@ -55,10 +55,14 @@ as follows:
booted with restricted memory. By default, the boot memory
size will be the larger of 5% of system RAM or 256MB.
Alternatively, user can also specify boot memory size
- through boot parameter 'fadump_reserve_mem=' which will
- override the default calculated size. Use this option
- if default boot memory size is not sufficient for second
- kernel to boot successfully.
+ through boot parameter 'crashkernel=' which will override
+ the default calculated size. Use this option if default
+ boot memory size is not sufficient for second kernel to
+ boot successfully. For syntax of crashkernel= parameter,
+ refer to Documentation/kdump/kdump.txt. If any offset is
+ provided in crashkernel= parameter, it will be ignored
+ as fadump reserves memory at end of RAM for boot memory
+ dump preservation in case of a crash.
-- After the low memory (boot memory) area has been saved, the
firmware will reset PCI and other hardware state. It will
@@ -158,13 +162,16 @@ How to enable firmware-assisted dump (fadump):
1. Set config option CONFIG_FA_DUMP=y and build kernel.
2. Boot into linux kernel with 'fadump=on' kernel cmdline option.
-3. Optionally, user can also set 'fadump_reserve_mem=' kernel cmdline
+3. Optionally, user can also set 'crashkernel=' kernel cmdline
to specify size of the memory to reserve for boot memory dump
preservation.
-NOTE: If firmware-assisted dump fails to reserve memory then it will
- fallback to existing kdump mechanism if 'crashkernel=' option
- is set at kernel cmdline.
+NOTE: 1. 'fadump_reserve_mem=' parameter has been deprecated. Instead
+ use 'crashkernel=' to specify size of the memory to reserve
+ for boot memory dump preservation.
+ 2. If firmware-assisted dump fails to reserve memory then it
+ will fallback to existing kdump mechanism if 'crashkernel='
+ option is set at kernel cmdline.
Sysfs/debugfs files:
------------
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