Re: perf: cannot resolve kernel symbols

[Namhyung Kim]

Hi Jean,

On Thu, 19 Sep 2013 15:24:56 +0200, Jean Pihet wrote:
> Hi,
>
> Ping on this issue. Any idea or pointer.

Did you build perf without libelf?

Thanks,
Namhyung

>
> Cheers,
> Jean
>
> On 17 September 2013 14:02, Jean Pihet <jean.pihet@xxxxxxxxxx> wrote:
>> Hi,
>>
>> I am running the perf record and report commands, which are running OK
>> but I do not get any kernel symbol resolved when using a built and
>> installed kernel.
>> Using the distro installed kernel is OK though.
>> The setup is: Marvell ARMv7 quad core, Linaro Ubuntu release.
>>
>> Here are the commands in use:
>> - perf record -g dwarf -- stress --cpu 2 --io 2 --vm 2 --timeout 1s
>> - perf report -vvv
>>
>> With a vmlinux found at /lib/modules/<version>/build I get the
>> following in the trace output:
>> ...
>> Looking at the vmlinux_path (6 entries long)
>> Using /lib/modules/3.11.0-00003-g0d4d4a1/build/vmlinux for symbols
>> ...
>> dso: [kernel.kallsyms]
>> (/lib/modules/3.11.0-00003-g0d4d4a1/build/vmlinux, Functions, loaded,
>> 0000000000000000000000000000000000000000)
>>  c00081c0-c00081c3 g asm_do_IRQ
>> ...
>> dso: [kernel.kallsyms].head.text ([kernel.kallsyms], Functions, loaded, 00000000
>> 00000000000000000000000000000000)
>>  c0008000-c0008077 g stext
>>  c0008000-c0008000 g _text
>>  c0008084-c0008127 l __create_page_tables
>> ...
>> dso: [kernel.kallsyms].init.text ([kernel.kallsyms], Functions, loaded, 00000000
>> 00000000000000000000000000000000)
>>  c04f3260-c04f32af l __fixup_smp
>>
>>
>> Without any vmlinux found I get the following:
>> ...
>> Looking at the vmlinux_path (6 entries long)
>> Using /proc/kallsyms for symbols
>> ...
>> dso: [kernel.kallsyms] ([kernel.kallsyms], Functions, loaded,
>> 0000000000000000000000000000000000000000)
>>  0-beffffff l __vectors_start
>> dso: [kernel.kallsyms] ([kernel.kallsyms], Variables, NOT loaded,
>> 0000000000000000000000000000000000000000)
>> dso: stress (/usr/bin/stress, Functions, loaded,
>> bdf57306ab106fb0ce9835c95dae5b173f238b61)
>> ...
>>
>>
>> In any case the symbols are not resolved although vmlinux contains
>> symbols and /proc/kallsyms is accessible and working correctly.
>> Any idea on where to look at? I guess the problem is in the kernel installation.
>>
>> Thx & regards,
>> Jean
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