1#!/usr/bin/perl -w
2# (c) 2009, Tom Zanussi <tzanussi@gmail.com>
3# Licensed under the terms of the GNU GPL License version 2
4
5# Display avg/min/max wakeup latency
6
7# The common_* event handler fields are the most useful fields common to
8# all events.  They don't necessarily correspond to the 'common_*' fields
9# in the status files.  Those fields not available as handler params can
10# be retrieved via script functions of the form get_common_*().
11
12use 5.010000;
13use strict;
14use warnings;
15
16use lib "$ENV{'PERF_EXEC_PATH'}/scripts/perl/Perf-Trace-Util/lib";
17use lib "./Perf-Trace-Util/lib";
18use Perf::Trace::Core;
19use Perf::Trace::Util;
20
21my %last_wakeup;
22
23my $max_wakeup_latency;
24my $min_wakeup_latency;
25my $total_wakeup_latency = 0;
26my $total_wakeups = 0;
27
28sub sched::sched_switch
29{
30    my ($event_name, $context, $common_cpu, $common_secs, $common_nsecs,
31	$common_pid, $common_comm,
32	$prev_comm, $prev_pid, $prev_prio, $prev_state, $next_comm, $next_pid,
33	$next_prio) = @_;
34
35    my $wakeup_ts = $last_wakeup{$common_cpu}{ts};
36    if ($wakeup_ts) {
37	my $switch_ts = nsecs($common_secs, $common_nsecs);
38	my $wakeup_latency = $switch_ts - $wakeup_ts;
39	if ($wakeup_latency > $max_wakeup_latency) {
40	    $max_wakeup_latency = $wakeup_latency;
41	}
42	if ($wakeup_latency < $min_wakeup_latency) {
43	    $min_wakeup_latency = $wakeup_latency;
44	}
45	$total_wakeup_latency += $wakeup_latency;
46	$total_wakeups++;
47    }
48    $last_wakeup{$common_cpu}{ts} = 0;
49}
50
51sub sched::sched_wakeup
52{
53    my ($event_name, $context, $common_cpu, $common_secs, $common_nsecs,
54	$common_pid, $common_comm,
55	$comm, $pid, $prio, $success, $target_cpu) = @_;
56
57    $last_wakeup{$target_cpu}{ts} = nsecs($common_secs, $common_nsecs);
58}
59
60sub trace_begin
61{
62    $min_wakeup_latency = 1000000000;
63    $max_wakeup_latency = 0;
64}
65
66sub trace_end
67{
68    printf("wakeup_latency stats:\n\n");
69    print "total_wakeups: $total_wakeups\n";
70    if ($total_wakeups) {
71	printf("avg_wakeup_latency (ns): %u\n",
72	       avg($total_wakeup_latency, $total_wakeups));
73    } else {
74	printf("avg_wakeup_latency (ns): N/A\n");
75    }
76    printf("min_wakeup_latency (ns): %u\n", $min_wakeup_latency);
77    printf("max_wakeup_latency (ns): %u\n", $max_wakeup_latency);
78
79    print_unhandled();
80}
81
82my %unhandled;
83
84sub print_unhandled
85{
86    if ((scalar keys %unhandled) == 0) {
87	return;
88    }
89
90    print "\nunhandled events:\n\n";
91
92    printf("%-40s  %10s\n", "event", "count");
93    printf("%-40s  %10s\n", "----------------------------------------",
94	   "-----------");
95
96    foreach my $event_name (keys %unhandled) {
97	printf("%-40s  %10d\n", $event_name, $unhandled{$event_name});
98    }
99}
100
101sub trace_unhandled
102{
103    my ($event_name, $context, $common_cpu, $common_secs, $common_nsecs,
104	$common_pid, $common_comm) = @_;
105
106    $unhandled{$event_name}++;
107}
108