Re: [Libunwind-devel] Time Cost of Libunwind is too expensive.

[Vladimir Nikulichev]

Hi Chenggang,

Do you use libunwind for either sampling or one-shot stack tracing?
For sampling Perf Events interface can be helpful for you.

For one shot have a look at this tool: https://github.com/tbricks/tbstack
Some numbers on Xeon(R) CPU E5-2690 0 @ 2.90GHz, for one thread: 
http://lists.nongnu.org/archive/html/libunwind-devel/2014-10/msg00008.html
Note that I measured time to freeze process and collect data, unwinding is 
completed afterwards.

—
Vladimir

> On 22 Nov 2014, at 12:05, Chenggang <address@hidden> wrote:
> 
> Hi:
>      I am a user of libunwind. I am developing a profiling system, "Bianque".
>      I use libunwind to unwind the stack on the target machine. But the time 
> cost is too expensive.
>      While the layers of call chain is 130 and the stack size is 1MB, we need 
> 3.8 milliseconds to unwind it.
>      My CPU is Xeon(R) CPU E5-2430 0 @ 2.20GHz.
>      Is this cost normal?
> 
> Regards
> Chenggang
>      
> 
> 
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