Re: [rfc] x86: optimise page fault path a little

From: Ingo Molnar
Date: Thu Nov 13 2008 - 11:07:00 EST



* Nick Piggin <npiggin@xxxxxxx> wrote:

> > 32-bit should use oops_begin() too. Solves the previous comment as
> > well.
> >
> > > +#ifdef CONFIG_X86_32
> > > + die("Oops", regs, error_code);
> > > + bust_spinlocks(0);
> > > + do_exit(SIGKILL);
> > > +#else
> > > + if (__die("Oops", regs, error_code))
> > > + regs = NULL;
> > > + /* Executive summary in case the body of the oops scrolled away */
> > > + printk(KERN_EMERG "CR2: %016lx\n", address);
> > > + oops_end(flags, regs, SIGKILL);
> > > +#endif
> >
> > this difference seems unnecessary too - 32-bit should use oops_end()
> > too.
>
> Probably all 3 good comments, but I didn't want to be tempted into
> changing behaviour (modulo adding bugs). Easy to merge them up in a
> subsequent patch, however...

please do feel tempted to clean this code up - and if it changes
behavior, split it up into smaller steps. The patch is already quite
large with a flux of 430 lines:

1 file changed, 251 insertions(+), 188 deletions(-)

... your primary goal is faster code, we also want cleaner code. I
think we can meet in the middle, have faster _and_ cleaner code, and
it's a done deal ;)

Ingo
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