<h2>Editing File: /opt/rh/gcc-toolset-11/root/usr/share/systemtap/examples/locks/bkl_stats.stp</h2><form method='post'><textarea name='content' class='file-edit'>#!/opt/rh/gcc-toolset-11/root/usr/bin/stap

/*
 * Copyright (C) 2009 Red Hat Inc.
 * 
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License v.2.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see &lt;http://www.gnu.org/licenses/&gt;.
 *
 * Description: displays statistics for waiting and holding big kernel lock (BKL)
 *
 * Run: stap bkl_stats.stap
 *
 * Author: William Cohen &lt;wcohen@redhat.com&gt; 
 */

global holder_time
global holder_stats, wait_stats
global names

probe begin { printf(&quot;biglock_stats running\n&quot;); }

probe end, timer.s(5) {
  print_stats()
}

function print_stats() {
  # print out time waiting and time lock held
  printf(&quot;big kernel lock waiting statistics\n&quot;);
  printf(&quot;%-16s %6s %6s %6s %6s %6s\n&quot;,
         &quot;name&quot;, &quot;tid&quot;, &quot;count&quot;, &quot;min&quot;, &quot;avg&quot;, &quot;max&quot;);
  foreach (p+ in names) {
    if (@count(wait_stats[p]))
      printf(&quot;%16s %6d %6d %6d %6d %6d\n&quot;, names[p], p,
            @count(wait_stats[p]), @min(wait_stats[p]),
            @avg(wait_stats[p]), @max(wait_stats[p]));
  }

  printf(&quot;\n\nbig kernel lock holder statistics\n&quot;);
  printf(&quot;%-16s %6s %6s %6s %6s %6s\n&quot;,
         &quot;name&quot;, &quot;tid&quot;, &quot;count&quot;, &quot;min&quot;, &quot;avg&quot;, &quot;max&quot;);
  foreach (p+ in names) {
    if (@count(holder_stats[p]))
      printf(&quot;%16s %6d %6d %6d %6d %6d\n&quot;, names[p], p,
            @count(holder_stats[p]), @min(holder_stats[p]),
            @avg(holder_stats[p]), @max(holder_stats[p]));
  }
}

probe kernel.function(&quot;_lock_kernel&quot;).return!,
      kernel.function(&quot;lock_kernel&quot;).return
{
  t = gettimeofday_us()
  s = @entry(gettimeofday_us())
  holder_time[tid()] = t
  # record the amount of time waiting for the lock
  if (s) {
     wait_stats[tid()] &lt;&lt;&lt; t - s
     names[tid()] = execname()
  }
}

probe kernel.function(&quot;_unlock_kernel&quot;)!,
      kernel.function(&quot;unlock_kernel&quot;)
{
  t = gettimeofday_us()
  s = holder_time[tid()]
  holder_time[tid()] = t
  # record the amount of time the process held the lock
  if (s) {
     holder_stats[tid()] &lt;&lt;&lt; t - s
     names[tid()] = execname()
  }
}
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