Hello,
Indeed there is a problem in the ARM code for tracepoints.
After a good discussion with the perf maintainers a solution has be
found, cf. http://www.spinics.net/lists/arm-kernel/msg332293.html.
Can you check if this fixes the problem? It does on my side on 3.15-rc4.
The patch is under review by the ARM experts and hopefully should be
merged soon.
Regards,
Jean
On 16 May 2014 09:34, Jean Pihet <jean.pi...@linaro.org> wrote:
> Hello,
>
>
> On 15 May 2014 07:36, sneha priya <sneha....@hotmail.com> wrote:
>> Hello,
>>
>> There is an issue related to perf which I am facing since 15 days. Hoping
>> that the great minds here will help me to solve this.
>>
>> I have a requirement to make perf tool work on a device having ARM
>> architecture. But, on recording the tracepoint events and then running
>> ./perf report, it shows the shared objects name as [unknown] and Symbols as
>> 00000, whereas for software and hardware events I do not experience this
>> issue.
>> I have cross compiled the perf tool available on mailine and ported it on a
>> device having ARM architecture.
>>
>> Output on ARM based device with kernel 3.4.
>>
>> ./perf record -e kmem:kmalloc cal
>>
>> [ perf record: Woken up 1 times to write data ]
>> [ perf record: Captured and wrote 0.007 MB perf.data (~321 samples) ]
>>
>> ./perf report
>>
>> Overhead Command Shared Object
>> Symbol
>> ........................... ................................
>> ...........................................
>> 40.78% cal [unknown]
>> [.]00000000
>> 31.6% cal [unknown]
>> [.]00000000
>>
>> [...]
>>
>> On ubuntu 12.04, system (kernel 3.10) it works perfectly fine.
>>
>> Output on x86 architecture
>>
>> ./perf record -e kmem:kmalloc gcalctool
>>
>> [ perf record: Woken up 3 times to write data ]
>> [ perf record: Captured and wrote 0.27 MB perf.data (~845 samples) ]
>>
>> ./perf report --stdio
>>
>> Overhead Command Shared
>> Object Symbol
>> ........................... ................................
>> ...........................................
>> 96.55% cal
>> [kernel.kallsyms] [k] kmem_cache_alloc_trace
>> 3.45% cal
>> [kernel.kallsyms] [.]__kmalloc
>>
>> [...]
>>
>>
>> Keenly, awaiting for you help.
>
> There are a few things to check. Note that the 3.4 kernel is OK wrt
> perf and tracepoints but is quite old, the recent development now
> happens on 3.15.
>
> - Do you have kallsyms enabled in your kernel (CONFIG_KALLSYMS=y)?
> - Are there warnings issued by perf record, e.g. access to kernel symbols etc?
> - perf report needs to know about your vmlinux image (the one that
> contains the debug symbols etc in the root directory of the kernel
> build). You can use '-k <file>' or '--vmlinux=<file>', cf. perf report
> --help.
> - You can dump the samples from perf.data using perf report -D. The
> entries with 'PERF_RECORD_SAMPLE(IP, 2)' are for the user space apps.
> - The '-v' option gives more info. This can be used multiple times ('-vv').
>
>>
>> Thanks.
>>
>> Sneha.
>
> Regards,
> Jean
>
>>
>> _______________________________________________
>> linaro-dev mailing list
>> linaro-dev@lists.linaro.org
>> http://lists.linaro.org/mailman/listinfo/linaro-dev
>>
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