Re: [Dle-develop] [RFC][PATCH -mmotm 1/4] Add static function calls of pstore to kexec path

[Matthew G. <mj...@re...>]

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 | mj...@sr...