Re: [RFC][PATCH] tracing/x86: Save CR2 before tracing irqsoff on error_entry

[Peter Zijlstra]

On Thu, Mar 21, 2019 at 02:10:20PM -0400, Steven Rostedt wrote:
> On Thu, 21 Mar 2019 11:05:06 -0700
> Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
> 
> > In the long run, I think the right solution is to rewrite even more of
> > this mess in C.  We really ought to be able to put the IRQ flag
> > tracing and the context tracking into C code.
> 
> And once we do that, we can work on getting the irq tracing
> incorporated into a jump_label type that we could possibly enable
> lockdep at start up, and then disable it later, even on production
> systems! That is, to be able to turn it off and bring the system back
> up to full speed.

You forget the stupid amount of data bloat that lockdep brings.