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perf top: Decay periods in callchains

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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 <acme@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1451963160-17196-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2016-01-05 12:06:00 +09:00 committed by Arnaldo Carvalho de Melo
parent 915b0882c3
commit 42b276a235
3 changed files with 30 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
tools/perf/util/callchain.c
View File

@ -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;

1
tools/perf/util/callchain.h
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@ -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 */

1
tools/perf/util/hist.c
View File

@ -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;