[PATCH 1/3] perf tools: Fix double count of total period
From: Frederic Weisbecker
Date: Sat Oct 15 2011 - 14:36:21 EST
When we resort the entries to fix the order of the hists after
we collapsed them, we count all the hists one more time,
recalculing the cols len, the stats, etc...
However we forget to reset the total period before doing that.
So the ending count is buggy.
When we resort the entries, we don't change their total numbers
or their content. So we can avoid to recompute the total period
and the len of the cols there.
This fixes the issue.
Before:
# Events: 23 cycles
#
# Overhead Command Shared Object Symbol
# ........ ....... ................. .....................
#
18.35% perf [kernel.kallsyms] [k] add_preempt_count
15.76% perf [kernel.kallsyms] [k] lock_is_held
15.22% sshd [kernel.kallsyms] [k] register_lock_class
0.17% swapper [kernel.kallsyms] [k] lock_release
0.17% perf [kernel.kallsyms] [k] lock_release
0.17% swapper [kernel.kallsyms] [k] __perf_event_enable
0.16% swapper [kernel.kallsyms] [k] native_write_msr_safe
0.00% perf [kernel.kallsyms] [k] native_write_msr_safe
After:
# Events: 23 cycles
#
# Overhead Command Shared Object Symbol
# ........ ....... ................. .....................
#
36.70% perf [kernel.kallsyms] [k] add_preempt_count
31.52% perf [kernel.kallsyms] [k] lock_is_held
30.43% sshd [kernel.kallsyms] [k] register_lock_class
0.35% swapper [kernel.kallsyms] [k] lock_release
0.34% perf [kernel.kallsyms] [k] lock_release
0.34% swapper [kernel.kallsyms] [k] __perf_event_enable
0.32% swapper [kernel.kallsyms] [k] native_write_msr_safe
0.01% perf [kernel.kallsyms] [k] native_write_msr_safe
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
---
tools/perf/util/hist.c | 4 ----
1 files changed, 0 insertions(+), 4 deletions(-)
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index a7193c5..bac6520 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -413,15 +413,11 @@ static void __hists__output_resort(struct hists *hists, bool threaded)
next = rb_first(root);
hists->entries = RB_ROOT;
- hists->nr_entries = 0;
- hists__reset_col_len(hists);
-
while (next) {
n = rb_entry(next, struct hist_entry, rb_node_in);
next = rb_next(&n->rb_node_in);
__hists__insert_output_entry(&hists->entries, n, min_callchain_hits);
- hists__inc_nr_entries(hists, n);
}
}
--
1.7.5.4
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