From 42b276a2351517409d55b1202a1fa8b05c0cdc99 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Tue, 5 Jan 2016 12:06:00 +0900 Subject: [PATCH] perf top: Decay periods in callchains It missed to decay periods in callchains when decaying hist entries. This resulted in more than 100 percent overhead in callchains in the fractal style output. Reported-by: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim Cc: Andi Kleen Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1451963160-17196-1-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/callchain.c | 28 ++++++++++++++++++++++++++++ tools/perf/util/callchain.h | 1 + tools/perf/util/hist.c | 1 + 3 files changed, 30 insertions(+) diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c index 564377d2bebf..53c43eb9489e 100644 --- a/tools/perf/util/callchain.c +++ b/tools/perf/util/callchain.c @@ -925,6 +925,34 @@ void free_callchain(struct callchain_root *root) free_callchain_node(&root->node); } +static u64 decay_callchain_node(struct callchain_node *node) +{ + struct callchain_node *child; + struct rb_node *n; + u64 child_hits = 0; + + n = rb_first(&node->rb_root_in); + while (n) { + child = container_of(n, struct callchain_node, rb_node_in); + + child_hits += decay_callchain_node(child); + n = rb_next(n); + } + + node->hit = (node->hit * 7) / 8; + node->children_hit = child_hits; + + return node->hit; +} + +void decay_callchain(struct callchain_root *root) +{ + if (!symbol_conf.use_callchain) + return; + + decay_callchain_node(&root->node); +} + int callchain_node__make_parent_list(struct callchain_node *node) { struct callchain_node *parent = node->parent; diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h index 8ac8f043004c..18dd22269764 100644 --- a/tools/perf/util/callchain.h +++ b/tools/perf/util/callchain.h @@ -253,6 +253,7 @@ int callchain_node__fprintf_value(struct callchain_node *node, FILE *fp, u64 total); void free_callchain(struct callchain_root *root); +void decay_callchain(struct callchain_root *root); int callchain_node__make_parent_list(struct callchain_node *node); #endif /* __PERF_CALLCHAIN_H */ diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c index afc9b8f1b36c..888776b43cb0 100644 --- a/tools/perf/util/hist.c +++ b/tools/perf/util/hist.c @@ -254,6 +254,7 @@ static bool hists__decay_entry(struct hists *hists, struct hist_entry *he) he_stat__decay(&he->stat); if (symbol_conf.cumulate_callchain) he_stat__decay(he->stat_acc); + decay_callchain(he->callchain); diff = prev_period - he->stat.period; -- 2.20.1