Re: perf on biarch

From: Matthieu CASTET
Date: Mon Aug 18 2014 - 05:16:48 EST


Le Fri, 8 Aug 2014 13:50:52 -0600,
David Ahern <dsahern@xxxxxxxxx> a écrit :

> On 8/8/14, 10:40 AM, Matthieu CASTET wrote:
> > Hi,
> >
> > I have a 64 bits kernel running with 32 bits binaries.
> > If I run 32 bits perf on this 64 bits kernel 3.14, I got weird result :
> >
> > - perf trace doesn't work [1]
>
> I have patches that fix that:
> git clone https://github.com/dsahern/linux.git
> git checkout perf-full-monty
>
> And if autodetection fails you can manually force it with -M x86.
>
Thanks david.
It is better, but it seems there are problem with argument parsing.

For example for
"mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0xf77e2000"
I got :
- 2.847 ( 0.004 ms): mmap2(arg0: 0, arg1: 0, arg2: 4096, arg3: 0, arg4:
3, arg5: 0 ) = -143273984


Note the 4096 position. Running perf trace on a 32 bits kernel give
4096 at arg1.


Matthieu
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