On Wed, Jan 08, 2014 at 05:46:15PM +0900, Namhyung Kim wrote: > It is possble that a callchain has cycles or recursive calls. In that > case it'll end up having entries more than 100% overhead in the > output. In order to prevent such entries, cache each callchain node > and skip if same entry already cumulated. > > Cc: Arun Sharma <[email protected]> > Cc: Frederic Weisbecker <[email protected]> > Signed-off-by: Namhyung Kim <[email protected]> > --- > tools/perf/builtin-report.c | 54 > ++++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 51 insertions(+), 3 deletions(-) > > diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c > index 06330736485b..087d01cac1aa 100644 > --- a/tools/perf/builtin-report.c > +++ b/tools/perf/builtin-report.c > @@ -363,7 +363,27 @@ static int > iter_prepare_cumulative_entry(struct hist_entry_iter *iter __maybe_unused, > struct addr_location *al __maybe_unused) > { > + struct callchain_cursor_node *node; > + struct hist_entry **he_cache; > + > callchain_cursor_commit(&callchain_cursor); > + > + /* > + * This is for detecting cycles or recursions so that they're > + * cumulated only one time to prevent entries more than 100% > + * overhead. > + */ > + he_cache = malloc(sizeof(*he_cache) * (PERF_MAX_STACK_DEPTH + 1)); > + if (he_cache == NULL) > + return -ENOMEM; > + > + iter->priv = he_cache; > + iter->curr = 0; > + > + node = callchain_cursor_current(&callchain_cursor); > + if (node == NULL) > + return 0;
some leftover? looks like nop.. jirka > + > return 0; > } > SNIP -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
