[PATCH v3 0/3] Merge ramoops and persistent_ram, generic pstore RAM backend

Anton Vorontsov anton.vorontsov at linaro.org
Thu May 17 07:11:48 UTC 2012

Hi all,

Here comes v3:

- Rebased on current staging-next tree, so only 3 patches left;
- Fixed ram_console dependency in Kconfig (issue noticed by Greg KH).

And the boilerplate, background for the series:

There are currently two competing debug facilities to store kernel
messages in a persistent storage: a generic pstore and Google's
persistent_ram. Not so long ago (https://lkml.org/lkml/2012/3/8/252),
it was decided that we should fix this situation.

Recently ramoops has switched to pstore, which basically means that
it became a RAM backend for the pstore framework.

persistent_ram+ram_console and ramoops+pstore have almost the same
features, except:

1. Ramoops doesn't support ECC. Having ECC is useful when a hardware
   reset was used to bring the machine back to life (i.e. a watchdog
   triggered). In such cases, RAM may be somewhat corrupt, but
   usually it is restorable.

2. Pstore doesn't support logging kernel messages in run-time, it only
   dumps dmesg when kernel oopses/panics. This makes pstore useless for
   debugging hangs caused by HW issues or improper use of HW (e.g.
   weird device inserted -> driver tried to write a reserved bits ->
   SoC hanged. In that case we don't get any messages in the pstore.

These patches solve the first issue, plus move things to their
proper places.

 Documentation/ramoops.txt                |    6 +
 drivers/staging/android/Kconfig          |   10 +-
 drivers/staging/android/Makefile         |    1 -
 drivers/staging/android/persistent_ram.c |  532 ------------------------------
 drivers/staging/android/persistent_ram.h |   82 -----
 drivers/staging/android/ram_console.c    |    2 +-
 fs/pstore/Kconfig                        |    7 +-
 fs/pstore/Makefile                       |    2 +-
 fs/pstore/ram.c                          |  119 ++++---
 fs/pstore/ram_core.c                     |  532 ++++++++++++++++++++++++++++++
 include/linux/pstore_ram.h               |   81 +++++
 11 files changed, 697 insertions(+), 677 deletions(-)

Anton Vorontsov
Email: cbouatmailru at gmail.com

More information about the devel mailing list