Messages in this thread | | | Subject | Re: [PATCH] perf annotate: Fix sample events lost in stdio mode | From | Yang Jihong <> | Date | Thu, 11 Mar 2021 16:48:18 +0800 |
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Hello,
On 2021/3/6 16:28, Yang Jihong wrote: > In hist__find_annotations function, since have a hist_entry per IP for the same > symbol, we free notes->src to signal already processed this symbol in stdio mode; > when annotate, entry will skipped if notes->src is NULL to avoid repeated output. > > However, there is a problem, for example, run the following command: > > # perf record -e branch-misses -e branch-instructions -a sleep 1 > > perf.data file contains different types of sample event. > > If the same IP sample event exists in branch-misses and branch-instructions, > this event uses the same symbol. When annotate branch-misses events, notes->src > corresponding to this event is set to null, as a result, when annotate > branch-instructions events, this event is skipped and no annotate is output. > > Solution of this patch is to add a u8 member to struct sym_hist and use a bit to > indicate whether the symbol has been processed. > Because different types of event correspond to different sym_hist, no conflict > occurs. > --- > tools/perf/builtin-annotate.c | 22 ++++++++++++++-------- > tools/perf/util/annotate.h | 4 ++++ > 2 files changed, 18 insertions(+), 8 deletions(-) > > diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c > index a23ba6bb99b6..c8c67892ae82 100644 > --- a/tools/perf/builtin-annotate.c > +++ b/tools/perf/builtin-annotate.c > @@ -372,15 +372,21 @@ static void hists__find_annotations(struct hists *hists, > if (next != NULL) > nd = next; > } else { > - hist_entry__tty_annotate(he, evsel, ann); > + struct sym_hist *h = annotated_source__histogram(notes->src, > + evsel->idx); > + > + if (h->processed == 0) { > + hist_entry__tty_annotate(he, evsel, ann); > + > + /* > + * Since we have a hist_entry per IP for the same > + * symbol, set processed flag of evsel in sym_hist > + * to signal we already processed this symbol. > + */ > + h->processed = 1; > + } > + > nd = rb_next(nd); > - /* > - * Since we have a hist_entry per IP for the same > - * symbol, free he->ms.sym->src to signal we already > - * processed this symbol. > - */ > - zfree(¬es->src->cycles_hist); > - zfree(¬es->src); > } > } > } > diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h > index 096cdaf21b01..89872bfdc958 100644 > --- a/tools/perf/util/annotate.h > +++ b/tools/perf/util/annotate.h > @@ -228,6 +228,10 @@ void symbol__calc_percent(struct symbol *sym, struct evsel *evsel); > struct sym_hist { > u64 nr_samples; > u64 period; > + > + u8 processed : 1, /* whether symbol has been processed, used for annotate */ > + __reserved : 7; > + > struct sym_hist_entry addr[]; > }; > > Please check whether this solution is feasible, look forward to your review.
Thanks, Yang
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