Re: perf: cannot resolve kernel symbols

From: Jean Pihet
Date: Thu Sep 19 2013 - 09:25:03 EST


Hi,

Ping on this issue. Any idea or pointer.

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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/