Re: [PATCH 2/5] perf tool: Initialize events IDs in a singlefunction

[Arnaldo Carvalho de Melo]

Em Sat, Nov 19, 2011 at 08:36:21PM -0500, Jiri Olsa escreveu:
> On Fri, Nov 18, 2011 at 12:22:55PM -0200, Arnaldo Carvalho de Melo wrote:
> > Em Fri, Nov 18, 2011 at 02:46:42PM +0100, Jiri Olsa escreveu:
> > > Currently events' IDs initialization is scattered among the
> > > code. Adding function 'perf_evlist__init_ids' to allocate
> > > and retrive events' IDs in one place.

> > I'm ok with this one, will merge it in my perf/core branch together with
> > a fix for a bug I noticed in the original code and that remains with
> > your changes: consider what happens if we do a second perf_evlist__mmap,
> > we will call perf_evlist__id_add_fd again and thus bump evsel->ids++
> > over nr_threads * nr_cpus, overflowing it.

> is there a valid scenario for this function to be called more than once?
> I'd think that just ensuring this is called once is enough

I don't know, I just don't want to preclude that, crystal balls are not
that reliable :-)

- Arnaldo
--
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/