Re: [PATCH 4/4] perf script: Add script to collect and display IBS samples

[Robert Richter <robert.richter@amd.com>]

Ingo,

On 08.03.12 13:19:24, Ingo Molnar wrote:
> I've applied the following 4 kernel patches to perf/x86-ibs:
> 
>  db98c5faf8cb: perf/x86: Implement 64-bit counter support for IBS
>  4db2e8e6500d: perf/x86: Implement IBS pmu control ops
>  b7074f1fbd61: perf/x86: Implement IBS interrupt handler
>  510419435c69: perf/x86: Implement IBS event configuration
> 
> and pushed it out.
> 
> We can apply any tooling changes to this branch as well.
> 
> I suspect being able to skid-less profile on AMD CPUs, using 
> IBS, would be a useful feature to users. What would be required 
> for that to work?

thanks for putting this into tip. This helps a lot.

I am just looking into skid-less sampling. The effort of attaching the
rip taken from the IBS sample for events 0x76/0xc1 should be feasable.

In between I started the implementation of ibs pseudo events as
described here:

 Appendix F Guide to Instruction-Based Sampling
 http://support.amd.com/us/Processor_TechDocs/47414_15h_sw_opt_guide.pdf

This includes kernel side filtering and ibs support for the perf tool.

-Robert

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Advanced Micro Devices, Inc.
Operating System Research Center