PermGen occupancy triggering CMS?

[Bernd Eckenfels]

On Fri, Sep 28, 2012 at 7:48 PM, Bernd Eckenfels
<bernd.eckenfels at googlemail.com> wrote:
> Do you know what will be the trigger
> for starting CMS when PermGen becomes full?

I found the following relevant(?) flags:

uintx AdaptivePermSizeWeight                    = 20
{product}
intx CMSInitiatingPermOccupancyFraction   = -1              {product}
bool CMSPermGenPrecleaningEnabled        = true            {product}
intx CMSTriggerPermRatio                           = 80
{product}
uintx MaxPermHeapExpansion                     = 5439488
{product}
uintx MaxPermSize                                     := 314572800
    {pd product}
uintx MinPermHeapExpansion                      = 327680
{product}
uintx PermGenPadding                                = 3
{product}
uintx PermMarkSweepDeadRatio                  = 20
{product}
uintx PermSize                                          :=  104857600
      {pd product}

So this seems like 80% should trigger, however in some places I found
the interpretation, that this means "only sweep permgen if more than
20% is used". The CMSInitiatingPermOccupancyFraction = -1 I understand
as: never initiate a cms by permgen occupancy? I should dig into the
code one time.