Messages in this thread | | | From | 河合英宏 / KAWAI,HIDEHIRO <> | Subject | RE: [V5 PATCH 2/4] panic/x86: Allow cpus to save registers even if they are looping in NMI context | Date | Wed, 25 Nov 2015 05:57:34 +0000 |
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> On Tue, Nov 24, 2015 at 11:48:53AM +0100, Borislav Petkov wrote: > > > > > + */ > > > + while (!raw_spin_trylock(&nmi_reason_lock)) > > > + poll_crash_ipi_and_callback(regs); > > > > Waaait a minute: so if we're getting NMIs broadcasted on every core but > > we're *not* crash dumping, we will run into here too. This can't be > > right. :-\ > > This only does something if crash_ipi_done is set, which means you are killing > the box. But perhaps a comment that states that here would be useful, or maybe > just put in the check here.
OK, I'll add more comments around this.
> There's no need to make it depend on SMP, as > raw_spin_trylock() will turn to just ({1}) for UP, and that code wont even be > hit.
I'll integrate these SMP and UP versions with a comment about that.
Regards, -- Hidehiro Kawai Hitachi, Ltd. Research & Development Group
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