Re: Re: [PATCH v2 1/5] perf probe: Split add_perf_probe_events()

[Namhyung Kim <namhyung@kernel.org>]

On Thu, Sep 10, 2015 at 08:10:16AM +0000, 平松雅巳 / HIRAMATU，MASAMI wrote:
> Hi Namhyung,
> 
> From: Namhyung Kim [mailto:namhyung@gmail.com] On Behalf Of Namhyung Kim
> >
> >Hi Masami,
> >
> >On Thu, Sep 10, 2015 at 05:00:07AM +0000, 平松雅巳 / HIRAMATU，MASAMI wrote:
> >> >From: Namhyung Kim [mailto:namhyung@gmail.com] On Behalf Of Namhyung Kim
> >> >The del_perf_probe_events() uses strfilter, but I think it can be
> >> >problematic if other instances or users are using similar events at
> >> >the same time.
> >>
> >> Yeah, since perf probe doesn't lock the ftrace, there should be a
> >> timing bug, but it can be fixed easily by ignoring -ENOENT. :)
> >
> >By ignoring -ENOENT?  Are you saying that there's a race between two
> >deleters?  Yes, of course, but I think that the bug will hit an adder
> >and a deleter especially if automatic probing is used (by eBPF and/or
> >SDT recording).
> 
> So, I don't think we need the automatic event removing. Instead, I'd like to
> suggest to keep it on the list.

But why?  Do you want reuse the probes for next record session?

I think if something is generated automatically, it should be removed
automatically..

Thanks,
Namhyung