Re: [PATCH 1/5] perf annotate: Split struct cycles_info
From: Namhyung Kim
Date: Mon Nov 06 2023 - 17:24:03 EST
Hi Arnaldo,
On Mon, Nov 6, 2023 at 11:53 AM Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
>
> Em Mon, Nov 06, 2023 at 04:34:51PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Fri, Nov 03, 2023 at 12:19:03PM -0700, Namhyung Kim escreveu:
> > > The cycles info is used only when branch stack is provided. Split them
> > > into a separate struct and lazy allocate them to save some memory.
> > >
> > > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> > > ---
> > > tools/perf/ui/browsers/annotate.c | 2 +-
> > > tools/perf/util/annotate.c | 34 ++++++++++++++++++-------------
> > > tools/perf/util/annotate.h | 14 ++++++++-----
> > > 3 files changed, 30 insertions(+), 20 deletions(-)
> > >
> > > diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c
> > > index ccdb2cd11fbf..d2470f87344d 100644
> > > --- a/tools/perf/ui/browsers/annotate.c
> > > +++ b/tools/perf/ui/browsers/annotate.c
> > > @@ -337,7 +337,7 @@ static void annotate_browser__calc_percent(struct annotate_browser *browser,
> > > max_percent = percent;
> > > }
> > >
> > > - if (max_percent < 0.01 && pos->al.ipc == 0) {
> > > + if (max_percent < 0.01 && (!pos->al.cycles || pos->al.cycles->ipc == 0)) {
> > > RB_CLEAR_NODE(&pos->al.rb_node);
> > > continue;
> > > }
> > > diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> > > index 82956adf9963..3e7f75827270 100644
> > > --- a/tools/perf/util/annotate.c
> > > +++ b/tools/perf/util/annotate.c
> > > @@ -1100,8 +1100,8 @@ static void annotation__count_and_fill(struct annotation *notes, u64 start, u64
> > > for (offset = start; offset <= end; offset++) {
> > > struct annotation_line *al = notes->offsets[offset];
> > >
> > > - if (al && al->ipc == 0.0) {
> > > - al->ipc = ipc;
> > > + if (al && al->cycles && al->cycles->ipc == 0.0) {
> > > + al->cycles->ipc = ipc;
> > > cover_insn++;
> > > }
> > > }
> > > @@ -1134,13 +1134,18 @@ void annotation__compute_ipc(struct annotation *notes, size_t size)
> > > if (ch && ch->cycles) {
> > > struct annotation_line *al;
> > >
> > > + al = notes->offsets[offset];
> > > + if (al && al->cycles == NULL) {
> > > + al->cycles = zalloc(sizeof(*al->cycles));
> > > + if (al->cycles == NULL)
> >
> > Shouldn't we stop here and tell the user that his system is really tight
> > on memory instead of just ignoring it?
> >
> > if (al->cycles == NULL) {
> > ui__error("Not enough memory for allocating branch stack cycles info!\n");
> > return ... its a void function :-\
> > }
> >
> > Since its a void function, can't we detect that we need al->cycles
> > allocated at the tool start and allocate it there, then propagate back
> > the error?
> >
> > Its per line, so doing it lazily is indeed easier, so make that function
> > return an error and bail out when not being able to calculate the ipc
> > for the remaining lines?
>
> I.e. with this folded into this patch, all but one of the callers of
> symbol__annotate2() already call a ui error messagem for instance:
>
> err = symbol__annotate2(ms, evsel, opts, &browser.arch);
> if (err) {
> char msg[BUFSIZ];
> dso->annotate_warned = true;
> symbol__strerror_disassemble(ms, err, msg, sizeof(msg));
> ui__error("Couldn't annotate %s:\n%s", sym->name, msg);
>
> - Arnaldo
Looks good to me, thanks for doing this!
Namhyung
>
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index 3e7f758272703554..99ff3bb9cad8daa6 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -1114,12 +1114,13 @@ static void annotation__count_and_fill(struct annotation *notes, u64 start, u64
> }
> }
>
> -void annotation__compute_ipc(struct annotation *notes, size_t size)
> +static int annotation__compute_ipc(struct annotation *notes, size_t size)
> {
> + int err = 0;
> s64 offset;
>
> if (!notes->src || !notes->src->cycles_hist)
> - return;
> + return 0;
>
> notes->total_insn = annotation__count_insn(notes, 0, size - 1);
> notes->hit_cycles = 0;
> @@ -1137,8 +1138,10 @@ void annotation__compute_ipc(struct annotation *notes, size_t size)
> al = notes->offsets[offset];
> if (al && al->cycles == NULL) {
> al->cycles = zalloc(sizeof(*al->cycles));
> - if (al->cycles == NULL)
> - continue;
> + if (al->cycles == NULL) {
> + err = ENOMEM;
> + break;
> + }
> }
> if (ch->have_start)
> annotation__count_and_fill(notes, ch->start, offset, ch);
> @@ -1150,7 +1153,21 @@ void annotation__compute_ipc(struct annotation *notes, size_t size)
> notes->have_cycles = true;
> }
> }
> +
> + if (err) {
> + while (++offset < (s64)size) {
> + struct cyc_hist *ch = ¬es->src->cycles_hist[offset];
> +
> + if (ch && ch->cycles) {
> + struct annotation_line *al = notes->offsets[offset];
> + if (al)
> + zfree(&al->cycles);
> + }
> + }
> + }
> +
> annotation__unlock(notes);
> + return 0;
> }
>
> int addr_map_symbol__inc_samples(struct addr_map_symbol *ams, struct perf_sample *sample,
> @@ -3270,7 +3287,11 @@ int symbol__annotate2(struct map_symbol *ms, struct evsel *evsel,
>
> annotation__set_offsets(notes, size);
> annotation__mark_jump_targets(notes, sym);
> - annotation__compute_ipc(notes, size);
> +
> + err = annotation__compute_ipc(notes, size);
> + if (err)
> + goto out_free_offsets;
> +
> annotation__init_column_widths(notes, sym);
> notes->nr_events = nr_pcnt;
>
> diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
> index 16d27952fd5c1b47..19bc2f03917575a8 100644
> --- a/tools/perf/util/annotate.h
> +++ b/tools/perf/util/annotate.h
> @@ -329,7 +329,6 @@ static inline bool annotation_line__filter(struct annotation_line *al, struct an
> }
>
> void annotation__set_offsets(struct annotation *notes, s64 size);
> -void annotation__compute_ipc(struct annotation *notes, size_t size);
> void annotation__mark_jump_targets(struct annotation *notes, struct symbol *sym);
> void annotation__update_column_widths(struct annotation *notes);
> void annotation__init_column_widths(struct annotation *notes, struct symbol *sym);