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@xxxxxxxxxx> 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>