LXR linux/tools/perf/scripts/perl/wakeup-latency.pl

   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