[PATCH v4 25/25] powernv/fadump: update documentation about option to release opalcore
hbathini at linux.ibm.com
Tue Jul 16 21:35:01 AEST 2019
With /sys/firmware/opal/core support available on OPAL based machines
and an option to the release memory used by kernel in exporting this
core file, update FADump documentation with these details.
Signed-off-by: Hari Bathini <hbathini at linux.ibm.com>
Documentation/powerpc/firmware-assisted-dump.txt | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/Documentation/powerpc/firmware-assisted-dump.txt b/Documentation/powerpc/firmware-assisted-dump.txt
index 373a9fb..9933fa6 100644
@@ -107,6 +107,16 @@ capture kernel boot to process this crash data. Kernel config
option CONFIG_PRESERVE_FA_DUMP has to be enabled on such kernel
to ensure that crash data is preserved to process later.
+-- On OPAL based machines (PowerNV), if the kernel is build with
+ CONFIG_OPAL_CORE=y, OPAL memory at the time of crash is also
+ exported as /sys/firmware/opal/core file. This procfs file is
+ helpful in debugging OPAL crashes with GDB. The kernel memory
+ used for exporting this procfs file can be released by echo'ing
+ '1' to /sys/kernel/fadump_release_opalcore node.
+ # echo 1 > /sys/kernel/fadump_release_opalcore
@@ -270,6 +280,15 @@ Here is the list of files under kernel sysfs:
enhanced to use this interface to release the memory reserved for
dump and continue without 2nd reboot.
+ This file is available only on OPAL based machines when FADump is
+ active during capture kernel. This is used to release the memory
+ used by the kernel to export /sys/firmware/opal/core file. To
+ release this memory, echo '1' to it:
+ echo 1 > /sys/kernel/fadump_release_opalcore
Here is the list of files under powerpc debugfs:
(Assuming debugfs is mounted on /sys/kernel/debug directory.)
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