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
  12 use 5.010000;
  13 use strict;
  14 use warnings;
  15
  16 use lib "$ENV{'PERF_EXEC_PATH'}/scripts/perl/Perf-Trace-Util/lib";
  17 use lib "./Perf-Trace-Util/lib";
  18 use Perf::Trace::Core;
  19 use Perf::Trace::Util;
  20
  21 my %last_wakeup;
  22
  23 my $max_wakeup_latency;
  24 my $min_wakeup_latency;
  25 my $total_wakeup_latency = 0;
  26 my $total_wakeups = 0;
  27
  28 sub sched::sched_switch
  29 {
  30     my ($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
  51 sub 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
  60 sub trace_begin
  61 {
  62     $min_wakeup_latency = 1000000000;
  63     $max_wakeup_latency = 0;
  64 }
  65
  66 sub 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
  82 my %unhandled;
  83
  84 sub 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
 101 sub 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 }