performance testing of UNWIND kernel option

[Martix]

Hi,
thanks for comparison.
I miss test with both CONFIG_ARM_UNWIND and CONFIG_FRAME_POINTER
disabled, theoreticaly it could be faster. Anyway, why regular user
(no developer, nor tester) needs to have CONFIG_ARM_UNWIND or
CONFIG_FRAME_POINTER enabled? I suggest to disable CONFIG_ARM_UNWIND
in stable kernel images. Stable I mean (in this case) kernel versions
which is well tested in SHR-t and stable revisions of Qt Moko.

Thanks Denis and Gennady.

Martin 'Martix' Holec
openmoko.cz/openmobility.cz


2011/3/8 Gennady Kupava <gb at bsdmn.com>:
> Hi, list.
>
> Today I noticed the following change in SHR:
> http://git.openembedded.org/cgit.cgi/openembedded/commit/?id=1516588acd3c4b4dd4add71d06ab8ce0d1bafa02 (by Denis 'GNUtoo' Carikli <GNUtoo at no-log.org>) and decided to lmbench it.
>
> Here are results: http://www.bsdmn.com/lmbench/unwind_summary.txt
>
> You can see comparison of:
>
> 34def -> kernel with CONFIG_FRAME_POINTER
> unwind -> kernel with CONFIG_ARM_UNWIND
> default -> for reference, old debugging kernel
>
> The unwind option provide clear benefit of 5%-10% in almost every area.
>
> Nice spot Denis!
>
> Gennady.
>
>
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