Messages in this thread | | | Date | Tue, 19 Jul 2011 19:52:13 +0100 | From | Matthew Garrett <> | Subject | Re: [RFC][PATCH -mmotm 1/4] Add static function calls of pstore to kexec path |
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On Tue, Jul 19, 2011 at 02:48:22PM -0400, Seiji Aguchi wrote: > >How is this safe? What happens if there's a pstore access in process > >when you hit this codepath? > > This will never happen because pstore_kmsg_dump_in_interrupt() is called after machine_crash_shutdown(). > > Panicked cpu sends NMI to all other cpus in machine_crash_shutdown() and they stop.
And how does that handle the case where we're halfway through a pstore access when the NMI arrives? ERST, at least, has a complex state machine. You can't guarantee what starting one transaction without completing one that was in process will do.
-- Matthew Garrett | mjg59@srcf.ucam.org
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