Re: [PATCH v4 0/8] Nvram-to-pstore

[Michael Neuling <mikey@neuling.org>]

Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com> wrote:

> Hi Michael,
> 
> On Wednesday 19 June 2013 11:45 AM, Michael Neuling wrote:
> > Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com> wrote:
> >> Currently the kernel provides the contents of p-series NVRAM only as a
> >> simple stream of bytes via /dev/nvram, which must be interpreted in user
> >> space by the nvram command in the powerpc-utils package. This patch set
> >> exploits the pstore subsystem to expose each partition in NVRAM as a
> >> separate file in /dev/pstore. For instance, Oops messages will be stored
> >> in a file named [dmesg-nvram-2].
> >>
> >> Changes from v3:
> >> 	- Change filename prefix for of-config and common partition
> >>
> >> Changes from v2:
> >> 	- Fix renaming of pstore type ids in nvram.c
> >>
> >> Changes from v1:
> >> 	- Reduce #ifdefs by and remove forward declarations of pstore callbacks
> >> 	- Handle return value of nvram_write_os_partition
> >> 	- Remove empty pstore callbacks and register pstore only when pstore
> >> 	  is configured
> > When booted on pHyp, I see /dev/nvram but not /dev/pstore, even if I
> > turn on CONFIG_PSTORE.  Is there something else I need to add?
> 
> You need to mount pstore to access the files.
> 
> # mkdir /dev/pstore
> # mount -t pstore - /dev/pstore
> 
> to unmount
> 
> # umount /dev/pstore
> 
> References: http://lwn.net/Articles/421297/
> Documentation/ABI/testing/pstore

Thanks

> 
> >
> > Should we update pseries_defconfig to include CONFIG_PSTORE (which it
> > doesn't include currently)?  Maybe turn on panic/oops via
> > CONFIG_PSTORE_RAM too?
> 
> Yes. We should enable CONFIG_PSTORE by default in pseries_defconfig.
> We need not enable CONFIG_PSTORE_RAM for our case. Its for systems with
> persistent RAM.

Please send addition patch to do this.

Mikey

> 
> > Other than that, the series looks clean.  It's passes my build and boot
> > tests.
> >
> > I've not reviewed the contents of the patches.
> >
> > Mikey
> >
> >> ---
> >>
> >> Aruna Balakrishnaiah (8):
> >>        powerpc/pseries: Remove syslog prefix in uncompressed oops text
> >>        powerpc/pseries: Add version and timestamp to oops header
> >>        powerpc/pseries: Introduce generic read function to read nvram-partitions
> >>        powerpc/pseries: Read/Write oops nvram partition via pstore
> >>        powerpc/pseries: Read rtas partition via pstore
> >>        powerpc/pseries: Distinguish between a os-partition and non-os partition
> >>        powerpc/pseries: Read of-config partition via pstore
> >>        powerpc/pseries: Read common partition via pstore
> >>
> >>
> >>   arch/powerpc/platforms/pseries/nvram.c |  353 +++++++++++++++++++++++++++-----
> >>   fs/pstore/inode.c                      |    9 +
> >>   include/linux/pstore.h                 |    4
> >>   3 files changed, 313 insertions(+), 53 deletions(-)
> >>
> >> -- 
> >>
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> >>
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