Re: [PATCH] perf, tool: Treat all memory maps without dso file asloaded

From: Jiri Olsa
Date: Thu Sep 29 2011 - 12:11:56 EST


On Wed, Aug 24, 2011 at 03:18:34PM +0200, Jiri Olsa wrote:
> On Mon, Aug 22, 2011 at 04:58:49PM +0200, Jiri Olsa wrote:
> > On Mon, Aug 22, 2011 at 11:11:30AM -0300, Arnaldo Carvalho de Melo wrote:
> > > Em Mon, Aug 22, 2011 at 09:53:22AM +0200, Jiri Olsa escreveu:
> > > > hi,
> > > > any feedback on this?
> > >
> > > Fell thru the cracks, sorry.
> > >
> > > > On Wed, Aug 10, 2011 at 02:44:11PM +0200, Jiri Olsa wrote:
> > > > > I get unnecessary warnings from map__load about "[stack]" maps,
> > > > > saying dso cannot be loaded.
> > >
> > > > > Attached patch avoids this warning for maps that are not backed-up
> > > > > by dso.
> > >
> > > > > I was wondering if we want to treat stack/heaps/vdso maps the same
> > > > > way or if there's something special about vdso in this regard.
> > > > > Because there could be another fix with setting all stack/heaps/vdso
> > > > > maps as loaded, which is probably little more nicer.
> > >
> > > Humm, in the vdso case we have a fallback in thread__find_addr_map, i.e.
> > > its symbol rbtree is empty, we notice that and lookup the symbol in the
> > > kernel symbol tables (vmlinux and modules).
> > >
> > > I.e. stack/heap symbols would not apply, this fallback wouldn't happen,
> > > the symbol would be unresolved, the patch then would be just to
> > > map__new, as:
> > >
> > > diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> > > index a16ecab..0c1c11b 100644
> > > --- a/tools/perf/util/map.c
> > > +++ b/tools/perf/util/map.c
> > > @@ -63,7 +63,9 @@ set_identity:
> > > } else if (strcmp(filename, "[vdso]") == 0) {
> > > dso__set_loaded(dso, self->type);
> > > goto set_identity;
> > > - }
> > > + } else if (strcmp(filename, "[heap]") == 0 ||
> > > + strcmp(filename, "[stack]") == 0)
> > > + dso__set_loaded(dso, self->type);
> > > }
> > > return self;
> > > out_delete:
> > >
> > > Right?
> >
> > yes, I was not completely sure I was not breaking anything else,
> > so I posted the first patch.. the original patch I had is attached.
> >
> > I haven't tested this one much though.. let me know and
> > I can resend this one with changelog/testing..
>
> and here it is ;)

hi,
any feedback?

thanks,
jirka






>
> thanks,
> jirka
>
> ---
> The stack/vdso/heap memory maps dont have any dso file.
> Setting the perf dso objects as 'loaded' for these maps,
> we avoid unnecessary warnings like:
>
> "Failed to open [stack], continuing without symbols"
>
> All map__find_* functions still return NULL when searching
> for symbols in these maps.
>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> tools/perf/util/map.c | 24 ++++++++++++++++++------
> 1 files changed, 18 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index a16ecab..7e218e3 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -18,6 +18,13 @@ static inline int is_anon_memory(const char *filename)
> return strcmp(filename, "//anon") == 0;
> }
>
> +static inline int is_no_dso_memory(const char *filename)
> +{
> + return !strcmp(filename, "[stack]") ||
> + !strcmp(filename, "[vdso]") ||
> + !strcmp(filename, "[heap]");
> +}
> +
> void map__init(struct map *self, enum map_type type,
> u64 start, u64 end, u64 pgoff, struct dso *dso)
> {
> @@ -42,9 +49,10 @@ struct map *map__new(struct list_head *dsos__list, u64 start, u64 len,
> if (self != NULL) {
> char newfilename[PATH_MAX];
> struct dso *dso;
> - int anon;
> + int anon, no_dso;
>
> anon = is_anon_memory(filename);
> + no_dso = is_no_dso_memory(filename);
>
> if (anon) {
> snprintf(newfilename, sizeof(newfilename), "/tmp/perf-%d.map", pid);
> @@ -57,12 +65,16 @@ struct map *map__new(struct list_head *dsos__list, u64 start, u64 len,
>
> map__init(self, type, start, start + len, pgoff, dso);
>
> - if (anon) {
> -set_identity:
> + if (anon || no_dso) {
> self->map_ip = self->unmap_ip = identity__map_ip;
> - } else if (strcmp(filename, "[vdso]") == 0) {
> - dso__set_loaded(dso, self->type);
> - goto set_identity;
> +
> + /*
> + * Set memory without DSO as loaded. All map__find_*
> + * functions still return NULL, and we avoid the
> + * unnecessary map__load warning.
> + */
> + if (no_dso)
> + dso__set_loaded(dso, self->type);
> }
> }
> return self;
> --
> 1.7.4
>
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