Re: frequent lockups in 3.18rc4

From: Linus Torvalds
Date: Thu Nov 20 2014 - 18:34:42 EST


On Thu, Nov 20, 2014 at 3:08 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
>
> What's the issue with nmi? Page faults are supposed to nest correctly
> inside nmi, right?

They should, now, yes. There used to be issues with the whole "that
re-enables NMI".

Which reminds me. We never took your patches that use ljmp to handle
the return-to-kernel mode. You did them for performance reasons, but I
think the bigger deal was that it would have cleaned up that whole
special case.

Or did they have other problems? The ones to return to user space were
admittedly more fun, but just a tad too crazy (and not _quite_ in the
"crazy like a fox" camp ;)

Linus
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