Messages in this thread | | | Date | Fri, 8 Jul 2011 22:49:41 +0100 | From | Matthew Garrett <> | Subject | Re: pstore dump inside an nmi handler |
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On Fri, Jul 08, 2011 at 02:40:13PM -0700, Luck, Tony wrote: > > Inside pstore_dump(), the first thing it tries to grab is a mutex_lock() > > (inside an nmi hander). This seems to be the root cause of my problems. > > Someone else pointed out that mutex_lock() is a problem here too. They > wondered whether spin_lock_irqsave() would work - or whether pstore > backends were allowed to sleep - to which I said I hoped they didn't, > but wasn't really sure what the future will hold.
EFI can't sleep (at least, not as far as the kernel's concerned), so we're safe there. I think it's fair to assume atomicity here - crash dumping is a pretty specific situation. Although we may need to think about whether pstore should be saving reboot and poweroff in that case.
-- Matthew Garrett | mjg59@srcf.ucam.org
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