Re: [PATCH V8 08/25] perf tools: Add Intel BTS support

[Adrian Hunter <adrian.hunter@intel.com>]

On 17/08/2015 6:52 p.m., Arnaldo Carvalho de Melo wrote:
> Em Fri, Jul 17, 2015 at 07:33:43PM +0300, Adrian Hunter escreveu:
>> Intel BTS support fits within the new auxtrace infrastructure.
>> Recording is supporting by identifying the Intel BTS PMU, parsing
>> options and setting up events.
>>
>> Decoding is supported by queuing up trace data by thread and then
>> decoding synchronously delivering synthesized event samples into the
>> session processing for tools to consume.
>
> So, I am not being able to reproduce the results from last time I tried
> it..
>
> [root@zoo ~]# uname -r
> 4.2.0-rc5+
>
> But all the DSOs are not being resolved :-\ Same machine, will try after lunch
> with a tip/master built kernel, right now I get this, perhaps that "81649
> instruction errors" message? I'll see what are the results with tip/master,
> meanwhile what I have is at the tmp.perf/intel_pt branch in my tree.
>
> - Arnaldo
>
> [root@zoo ~]# perf record --per-thread -e intel_bts// usleep 1
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 1.884 MB perf.data ]
> [root@zoo ~]# perf evlist
> intel_bts//
> dummy:u
> [root@zoo ~]# perf evlist -v
> intel_bts//: type: 6, size: 112, { sample_period, sample_freq }: 1,
> sample_type: IP|TID|IDENTIFIER, read_format: ID, disabled: 1,
> enable_on_exec: 1, sample_id_all: 1, exclude_guest: 1
> dummy:u: type: 1, size: 112, config: 0x9, { sample_period, sample_freq
> }: 1, sample_type: IP|TID|IDENTIFIER, read_format: ID, disabled: 1,
> exclude_kernel: 1, exclude_hv: 1, mmap: 1, comm: 1, enable_on_exec: 1,
> task: 1, sample_id_all: 1, mmap2: 1, comm_exec: 1
> [root@zoo ~]#
>
> Warning:
> 81649 instruction trace errors
> # To display the perf.data header info, please use --header/--header-only options.
> #
> #
> # Total Lost Samples: 0
> #
> # Samples: 0  of event 'intel_bts//'
> # Event count (approx.): 0
> #
> # Overhead  Command  Shared Object  Symbol
> # ........  .......  .............  ......
> #
>
>
> # Samples: 0  of event 'dummy:u'
> # Event count (approx.): 0
> #
> # Overhead  Command  Shared Object  Symbol
> # ........  .......  .............  ......
> #
>
>
> # Samples: 81K of event 'branches'
> # Event count (approx.): 81649
> #
> # Overhead  Command  Shared Object     Symbol
> # ........  .......  ................  ......................
> #
>       2.71%  usleep   [unknown]         [.] 0x00007fa0ff695061
>       2.62%  usleep   [unknown]         [.] 0x00007fa0ffb3de7e
>       1.96%  usleep   [unknown]         [.] 0x00007fa0ffb2e726
>       1.92%  usleep   [unknown]         [.] 0x00007fa0ff695086
>       1.60%  usleep   [unknown]         [.] 0xffffffff811c91d0
>       1.48%  usleep   [unknown]         [.] 0x00007fa0ffb3030d
>       1.24%  usleep   [unknown]         [.] 0x00007fa0ff6950c7
>
>
>
>

It is very weird that it doesn't know the dso.

I presume there is nothing unusual about the environment e.g. in a chroot or anything

What if you try a different event e.g. perf record --per-thread -e cycles sleep 1