Re: [PATCH] ARM: perf: Implement perf_arch_fetch_caller_regs

[Will Deacon]

On Sat, Jul 20, 2013 at 04:43:21AM +0100, Jed Davis wrote:
> On Mon, Jul 15, 2013 at 02:53:42PM +0100, Will Deacon wrote:
> > > +				     "mov %[_pc],  r15\n\t"		\
> > > +				     "mrs %[_cpsr], cpsr\n\t"		\
> > > +				     : [_cpsr] "=r" (_cpsr),		\
> > > +				       [_pc] "=r" (_pc)			\
> > > +				     : [_regs] "r" (&(regs)->uregs)	\
> > 
> > It would be cleaner to pass a separate argument for each register, using the
> > ARM_rN macros rather than calculating the offset by hand.
> 
> I'll do that.  If there were more arguments there might be a problem
> at -O0, because the naive translation can run out of registers in
> some cases, but that shouldn't be a problem here.  (Nor if someone
> later extends this to all the core registers, because {r0-r13} can and
> presumably should use a store-multiple.)

We already rely on compiler optimisation for things like tlbflush.h, so we
don't need to worry about building with -O0.

Please send a v2 when you get a chance!

Will
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/