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authorHari Bathini <hbathini@linux.vnet.ibm.com>2017-05-08 15:56:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-08 17:15:11 -0700
commit92019efc6cf2126edc482342446f1252d091081a (patch)
treeb8fc826b9be03266fb455745ed0cf6b4c85ab10c
parent11550dc0a00b793236e8dedcf1f489f4627ddf7e (diff)
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 <hbathini@linux.vnet.ibm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--Documentation/powerpc/firmware-assisted-dump.txt23
1 files changed, 15 insertions, 8 deletions
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:
------------