Re: perf probe -F with wildcards

From: Arnaldo Carvalho de Melo
Date: Fri Jul 15 2016 - 09:14:49 EST


Em Fri, Jul 15, 2016 at 04:15:48PM +0900, Masami Hiramatsu escreveu:
> On Thu, 14 Jul 2016 21:16:41 -0300
> Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:

> > 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.

Yeah, that is the problem at hand, I figured there weren't functions
liek that, but the error message was tottally misleading :-)

> - 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.

Right,

- Arnaldo