+sub _diffms
+{
+ return unless isdbg('chan');
+ my $call = shift;
+ my $a = shift;
+ my $b = shift || [gettimeofday];
+ my $prefix = shift;
+
+ my $secs = $b->[0] - $a->[0];
+ my $msecs = int(($b->[1] - $a->[1]) / 1000);
+
+ my $s = "forkcall stats: $call ";
+ $s .= "$prefix " if $prefix;
+ $s .= "${secs}S" if $secs;
+ $s .= "${msecs}mS";
+ dbg($s);
+}
+