From: Daniel Walker <dwalker@fifo99.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Avery Pennarun <apenwarr@gmail.com>,
Josh Triplett <josh@joshtriplett.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Ingo Molnar <mingo@elte.hu>,
"David S. Miller" <davem@davemloft.net>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
"Fabio M. Di Nitto" <fdinitto@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Olaf Hering <olaf@aepfle.de>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Tejun Heo <tj@kernel.org>, "H. Peter Anvin" <hpa@linux.intel.com>,
Yinghai LU <yinghai@kernel.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Seiji Aguchi <seiji.aguchi@hds.com>
Subject: Re: [PATCH 0/5] Persist printk buffer across reboots.
Date: Tue, 13 Mar 2012 19:19:06 -0700 [thread overview]
Message-ID: <20120314021906.GC5218@fifo99.com> (raw)
In-Reply-To: <20120313151049.fa33d232.akpm@linux-foundation.org>
On Tue, Mar 13, 2012 at 03:10:49PM -0700, Andrew Morton wrote:
> On Tue, 13 Mar 2012 10:08:51 -0700
> Daniel Walker <dwalker@fifo99.com> wrote:
>
> > On Tue, Mar 13, 2012 at 01:36:36AM -0400, Avery Pennarun wrote:
> > > The last patch in this series implements a new CONFIG_PRINTK_PERSIST option
> > > that, when enabled, puts the printk buffer in a well-defined memory location
> > > so that we can keep appending to it after a reboot. The upshot is that,
> > > even after a kernel panic or non-panic hard lockup, on the next boot
> > > userspace will be able to grab the kernel messages leading up to it. It
> > > could then upload the messages to a server (for example) to keep crash
> > > statistics.
> >
> > There's currently driver/mtd/mtdoops.c, fs/pstore/, and
> > drivers/staging/android/ram_console.c that do similar things
> > as this. Did you investigate those for potentially modifying them to add
> > this functionality ? If so what issues did you find?
> >
> > I have a arm MSM G1 with persistent memory at 0x16d00000 size 20000bytes..
> > It's fairly simple you just have to ioremap the memory, but then it's good
> > for writing.. Currently the android ram_console uses this. How would I
> > convert this area for use with your changes?
>
> Yes, and various local implementations which do things such as stuffing
> the log buffer into NVRAM as the kernel is crashing.
>
> I do think we'd need some back-end driver arrangement which will permit
> the use of stores which aren't in addressible mamory.
>
> It's quite the can of worms, but definitely worth doing if we can get
> it approximately correct.
For sure.. I've had at least a couple non-OOPS based crashed I would
have liked to get logs for.
There is also this series,
http://lists.infradead.org/pipermail/kexec/2011-July/005258.html
It seems awkward that pstore is in fs/pstore/ then pstore ends up as the
"back end" where it could just be the whole solution.
Daniel
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next prev parent reply other threads:[~2012-03-14 2:19 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-13 5:36 [PATCH 0/5] Persist printk buffer across reboots Avery Pennarun
2012-03-13 5:36 ` [PATCH 1/5] mm: bootmem: BUG() if you try to allocate bootmem too late Avery Pennarun
2012-03-13 5:36 ` [PATCH 2/5] mm: bootmem: it's okay to reserve_bootmem an invalid address Avery Pennarun
2012-03-13 5:36 ` [PATCH 3/5] mm: nobootmem: implement reserve_bootmem() in terms of memblock Avery Pennarun
2012-03-13 5:36 ` [PATCH 4/5] printk: use alloc_bootmem() instead of memblock_alloc() Avery Pennarun
2012-03-13 6:13 ` Yinghai Lu
2012-03-13 6:40 ` Avery Pennarun
2012-03-13 8:26 ` Ingo Molnar
2012-03-13 21:50 ` Yinghai Lu
2012-03-14 2:23 ` Avery Pennarun
2012-03-13 5:36 ` [PATCH 5/5] printk: CONFIG_PRINTK_PERSIST: persist printk buffer across reboots Avery Pennarun
2012-03-13 5:53 ` [PATCH 0/5] Persist " David Miller
2012-03-13 6:00 ` Avery Pennarun
2012-03-13 6:50 ` David Miller
2012-03-13 7:14 ` Avery Pennarun
2012-03-13 7:18 ` David Miller
2012-03-13 8:10 ` Avery Pennarun
2012-03-13 8:16 ` David Miller
2012-03-13 13:50 ` Peter Zijlstra
2012-03-14 1:57 ` Daniel Walker
2012-03-13 8:32 ` Stephen Boyd
2012-03-13 17:08 ` Daniel Walker
2012-03-13 22:10 ` Andrew Morton
2012-03-14 2:19 ` Daniel Walker [this message]
2012-03-15 22:10 ` Seiji Aguchi
2012-03-14 2:21 ` Avery Pennarun
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