Re: perf probe -F with wildcards

From: Masami Hiramatsu
Date: Fri Jul 15 2016 - 03:16:29 EST


Hi Arnaldo,

On Thu, 14 Jul 2016 21:16:41 -0300
Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:

> Hi Masami,
>
> I think this worked at some point?
>
> [root@jouet acme]# perf probe -F | tail
> zswap_frontswap_init
> zswap_frontswap_invalidate_area
> zswap_frontswap_invalidate_page
> zswap_frontswap_load
> zswap_frontswap_store
> zswap_pool_create
> zswap_pool_current
> zswap_update_total_size
> zswap_writeback_entry
> zswap_zpool_param_set
> [root@jouet acme]# perf probe -F rt_sp*
> no symbols found in [kernel.kallsyms], maybe install a debug package?
> Failed to load symbols in kernel

It seems that 2 problems we have,
- There is no function which starts with rt_sp.
- The error message is not good for that.
If you try perf probe -F acpi_*, you'll see a list of functions.

> [root@jouet acme]# perf probe -F rt_sp\*
> no symbols found in [kernel.kallsyms], maybe install a debug package?
> Failed to load symbols in kernel

So, yeah, it should check symbol loading is really failed and should be
changed as "no symbols match to given filter" etc.

Thank you,

> [root@jouet acme]#


>
>
> I.e. the second message is misleading :-\
>
> - Arnaldo
>


--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>