[PATCH] testbot: Add the $MaxRunningVMs limit.

[Francois Gouget]

This allows preparing up to $MaxActiveVMs idle VMs while putting a
lower limit on the number of simultaneously running tasks.

Signed-off-by: Francois Gouget 
---

This patch is just to introduce the parameter and associated code. So 
$MaxRunningVMs is set to 1 by default and thus there should be no change 
in the TestBot behavior.
Later on we can play with this parameter to see if another value would 
be better.

testbot/bin/Engine.pl             | 6 ++++++
 testbot/lib/WineTestBot/Config.pm | 6 ++++--
 testbot/lib/WineTestBot/Jobs.pm   | 7 ++++++-
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/testbot/bin/Engine.pl b/testbot/bin/Engine.pl
index 7e278ba97..2e62c660c 100755
--- a/testbot/bin/Engine.pl
+++ b/testbot/bin/Engine.pl
@@ -736,6 +736,12 @@ sub main()

# Validate and adjust the configuration options
   $MaxActiveVMs ||= 1;
+  $MaxRunningVMs ||= $MaxActiveVMs;
+  if ($MaxRunningVMs > $MaxActiveVMs)
+  {
+    $MaxRunningVMs = $MaxActiveVMs;
+    LogMsg "Capping MaxRunningVMs to MaxActiveVMs ($MaxRunningVMs)\n";
+  }
   $MaxRevertingVMs ||= $MaxActiveVMs;
   if ($MaxRevertingVMs > $MaxActiveVMs)
   {
diff --git a/testbot/lib/WineTestBot/Config.pm b/testbot/lib/WineTestBot/Config.pm
index 2c615fadb..a425e4909 100644
--- a/testbot/lib/WineTestBot/Config.pm
+++ b/testbot/lib/WineTestBot/Config.pm
@@ -27,7 +27,8 @@ WineTestBot::Config - Site-independent configuration settings

use vars qw (@ISA @EXPORT @EXPORT_OK $UseSSL $LogDir $DataDir $BinDir
              $DbDataSource $DbUsername $DbPassword $MaxRevertingVMs
-             $MaxRevertsWhileRunningVMs $MaxActiveVMs $MaxVMsWhenIdle
+             $MaxRevertsWhileRunningVMs $MaxActiveVMs $MaxRunningVMs
+             $MaxVMsWhenIdle
              $SleepAfterRevert $WaitForToolsInVM $MaxTaskTries $AdminEMail
              $RobotEMail
              $WinePatchToOverride $WinePatchCc $SuiteTimeout $SingleTimeout
@@ -42,7 +43,7 @@ require Exporter;
 @ISA = qw(Exporter);
 @EXPORT = qw($UseSSL $LogDir $DataDir $BinDir
              $MaxRevertingVMs $MaxRevertsWhileRunningVMs $MaxActiveVMs
-             $MaxVMsWhenIdle $SleepAfterRevert $WaitForToolsInVM
+             $MaxRunningVMs $MaxVMsWhenIdle $SleepAfterRevert $WaitForToolsInVM
              $MaxTaskTries $AdminEMail
              $RobotEMail $WinePatchToOverride $WinePatchCc $SuiteTimeout
              $SingleTimeout $BuildTimeout $ReconfigTimeout
@@ -69,6 +70,7 @@ $BinDir = "$::RootDir/bin";
 $MaxRevertingVMs = 1;
 $MaxRevertsWhileRunningVMs = 0;
 $MaxActiveVMs = 2;
+$MaxRunningVMs = 1;
 $MaxVMsWhenIdle = undef;

# How long to wait for each of the 3 connection attempts to the VM's TestAgent
diff --git a/testbot/lib/WineTestBot/Jobs.pm b/testbot/lib/WineTestBot/Jobs.pm
index 9a0f8bc39..b71073adb 100644
--- a/testbot/lib/WineTestBot/Jobs.pm
+++ b/testbot/lib/WineTestBot/Jobs.pm
@@ -473,6 +473,7 @@ sub _GetSchedHost($$)
       MaxRevertingVMs => $MaxRevertingVMs,
       MaxRevertsWhileRunningVMs => $MaxRevertsWhileRunningVMs,
       MaxActiveVMs => $MaxActiveVMs,
+      MaxRunningVMs => $MaxRunningVMs,
       MaxVMsWhenIdle => $MaxVMsWhenIdle,
     };
   }
@@ -905,7 +906,11 @@ sub _ScheduleTasks($)
           delete $Sched->{lambvms}->{$VMKey};

my $Host = _GetSchedHost($Sched, $VM);
-          if ($Host->{active} - $Host->{idle} < $Host->{MaxActiveVMs} and
+          # Dirty VMs are VMs that were running and have still not been
+          # powered off. Sleeping VMs may be VMs that are booting.
+          # So in both cases they may still be using CPU and I/O resources so
+          # count them against the running VM limit.
+          if ($Host->{sleeping} + $Host->{running} + $Host->{dirty} < $Host->{MaxRunningVMs} and
               ($Host->{reverting} == 0 or
                $Host->{reverting} <= $Host->{MaxRevertsWhileRunningVMs}))
           {