From 92019efc6cf2126edc482342446f1252d091081a Mon Sep 17 00:00:00 2001 From: Hari Bathini Date: Mon, 8 May 2017 15:56:31 -0700 Subject: powerpc/fadump: update documentation about crashkernel parameter reuse 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. Link: http://lkml.kernel.org/r/149035347559.6881.14224829694291758581.stgit@hbathini.in.ibm.com Signed-off-by: Hari Bathini Acked-by: Michael Ellerman Cc: Fenghua Yu Cc: Tony Luck Cc: Dave Young Cc: Eric Biederman Cc: Mahesh Salgaonkar Cc: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/powerpc/firmware-assisted-dump.txt | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) (limited to 'Documentation/powerpc/firmware-assisted-dump.txt') diff --git a/Documentation/powerpc/firmware-assisted-dump.txt b/Documentation/powerpc/firmware-assisted-dump.txt index 19b1e3d09a19..9cabaf8a207e 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: ------------ -- cgit v1.2.3-59-g8ed1b