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| author | Hari Bathini <hbathini@linux.ibm.com> | 2019-09-11 20:27:12 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-09-14 00:04:45 +1000 |
| commit | b3bba79d5a7ba27bf7e31e124afbcb386128f2c6 (patch) | |
| tree | 5a733dc169256d0d3b415df03f5ce5b6f597b7d1 | |
| parent | 7b1b3b48250acbfd7f15ba950d4654b7f02a8300 (diff) | |
| download | lwn-b3bba79d5a7ba27bf7e31e124afbcb386128f2c6.tar.gz lwn-b3bba79d5a7ba27bf7e31e124afbcb386128f2c6.zip | |
powerpc/fadump: update documentation about option to release opalcore
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@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821382786.5656.13173494907671241231.stgit@hbathini.in.ibm.com
| -rw-r--r-- | Documentation/powerpc/firmware-assisted-dump.rst | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/Documentation/powerpc/firmware-assisted-dump.rst b/Documentation/powerpc/firmware-assisted-dump.rst index 08a9b5efcdc8..0455a78486d5 100644 --- a/Documentation/powerpc/firmware-assisted-dump.rst +++ b/Documentation/powerpc/firmware-assisted-dump.rst @@ -110,6 +110,16 @@ 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. + + e.g. + # echo 1 > /sys/kernel/fadump_release_opalcore + Implementation details: ----------------------- @@ -273,6 +283,15 @@ 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. + /sys/kernel/fadump_release_opalcore + + 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.) |