Review request (M): 7085906: Replace the permgen allocated sentinelRef with a self-looped end

Stefan Karlsson stefan.karlsson at oracle.com
Mon Sep 5 10:54:37 PDT 2011


Ramki,

On 09/05/2011 07:38 PM, Ramki Ramakrishna wrote:
> Stefan, this looks good to me. (PS: I am assuming this is 
> substantively the same code I reviewed
> last week? Let me know if there are any subsequent changes I need to 
> be specially
> aware of, or to pull into my testing.)

This is essentially the same code (I removed the unused function 
declaration that was present in last weeks code).

thanks,
StefanK

>
> thanks!
> -- ramki
>
> On 9/5/2011 4:59 AM, Stefan Karlsson wrote:
>> http://cr.openjdk.java.net/~stefank/7085906/webrev/
>>
>> 7085906: Replace the permgen allocated sentinelRef with a self-looped 
>> end
>>
>> The reference processor uses the sentinelRef to mark the end of the 
>> lists of discovered References. All the collectors rely on the 
>> sentinelRef being allocated in the permgen, hence not moving. So, 
>> when permgen is removed this will not work.
>>
>> We could probably make changes to the collectors to update all 
>> pointers to the sentinelRef, but the proposed solution is to remove 
>> the sentinelRef, and instead let the last Reference in a discovered 
>> chain point back to itself. Just like we do with the next field.
>>
>> StefanK



More information about the hotspot-gc-dev mailing list