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Re: [RFC] Lock elision "test suite", first draft
- From: OndÅej BÃlka <neleai at seznam dot cz>
- To: libc-alpha at sourceware dot org
- Date: Wed, 7 Aug 2013 14:20:10 +0200
- Subject: Re: [RFC] Lock elision "test suite", first draft
- References: <20130806093649 dot GA23477 at linux dot vnet dot ibm dot com> <20130807120723 dot GA7829 at linux dot vnet dot ibm dot com>
On Wed, Aug 07, 2013 at 02:07:23PM +0200, Dominik Vogt wrote:
> Test results on z/Architecture (zEC12)
> --------------------------------------
>
> Test Setup:
>
> An lpar with eight CPUs on a ZEC12. 8 GiB RAM.
>
> Test execution:
>
> Each test case was run ten times in a loop using an unpatched
> glibc-2.15 (Ubuntu standard) ("old glibc"), a new glibc-2.18
> with elision disabled ("elision n/a"), and a new glibc-2.18
> with elision enabled ("elision on").
snip
> ./ets-t3
> =========
>
> old glibc:
> ----------
> pct_best : 100.00...%
> pct_mindev: 4.57...%
> pct_maxdev: 5.43...%
> pct_stddev: 3.61...%
>
> elision n/a:
> ------------
> pct_best : 96.79...%
> pct_mindev: 9.82...%
> pct_maxdev: 9.42...%
> pct_stddev: 5.71...%
>
> elision on:
> -----------
> pct_best 593.48...%
> pct_mindev: 5.73...%
> pct_maxdev: 4.09...%
> pct_stddev: 3.43...%
>
Do you know why elision is 6 times slower on this test?