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

To: "Ralf Baechle" <>
Subject: Re: [PATCH 1/7] signals: reduce {setup,restore}_sigcontext sizes
From: "Franck Bui-Huu" <>
Date: Wed, 24 Jan 2007 13:25:27 +0100
Cc:, "Franck Bui-Huu" <>
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On 1/23/07, Ralf Baechle <> wrote:
On Tue, Jan 23, 2007 at 03:18:17PM +0100, Franck Bui-Huu wrote:

> From: Franck Bui-Huu <>
> 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

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.


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