Re: [PATCH 1/7] signals: reduce {setup,restore}_sigcontext sizes

["Franck Bui-Huu" <vagabon.xyz@gmail.com>]

On 1/23/07, Ralf Baechle <ralf@linux-mips.org> wrote:
> On Tue, Jan 23, 2007 at 03:18:17PM +0100, Franck Bui-Huu wrote:
>
> > From: Franck Bui-Huu <fbuihuu@gmail.com>
> >
> > This trivial change reduces considerably code size of these
> > 2 functions callers. For instance, here is the figures for
> > arch/kernel/signal.o objects:
> >
> >    text    data     bss     dec     hex filename
> >   11972       0       0   11972    2ec4 arch/mips/kernel/signal.o~old
> >    5380       0       0    5380    1504 arch/mips/kernel/signal.o~new
>
> Have you ran any benchmarks on this?  Unrolling the loops used to make
> a noticable difference.
OK, I ran a micro benchmark on setup_frame() which calls
setup_sigcontext(). I got the execution time of setup_frame() by
counting the number of cycles spent in it (by using cp0_count
register).

Without this patchset applied it takes about 14600 cycles for
setup_frame() execution whereas with this patchset applied it takes
10300 cycles. These figures are averages.

So it appears that this patchset has a positive impact on both size and speed.

thanks
--
              Franck