Fwd: Re: Request for review: 8004132 SerialGC ValidateMarkSweep code broken

[Jon Masamitsu]

Tao,

Changes look good.

Jon

On 12/20/12 14:19, Tao Mao wrote:
> Hi hotspot-dev,
> Is there anyone interested in reviewing the change?
>
> Thanks.
> Tao
>
> -------- Original Message --------
> Subject:     Re: Request for review: 8004132 SerialGC 
> ValidateMarkSweep code broken
> Date:     Mon, 17 Dec 2012 13:02:15 -0800
> From:     Tao Mao <tao.mao at oracle.com>
> Organization:     Oracle Corporation
> To:     John Cuthbertson <john.cuthbertson at oracle.com>
> CC:     hotspot-gc-dev openjdk.java.net <hotspot-gc-dev at openjdk.java.net>
>
>
>
> Thank you, John. A new webrev is uploaded as you advised.
>
> http://cr.openjdk.java.net/~tamao/8004132/webrev.01/
>
> I would like to have one more review if possible.
>
> Thanks.
> Tao
>
> On 12/13/2012 4:05 PM, John Cuthbertson wrote:
>>  Hi Tao,
>>
>>  This looks good to me. One comment - the functionality of
>>  RecordMarkSweepCompaction depends upon ValidateMarkSweep you might
>>  want to remove this flag as well.
>>
>>  JohnC
>>
>>  On 12/04/12 15:47, Tao Mao wrote:
>>>  8004132 : SerialGC: ValidateMarkSweep broken when running GCOld
>>>  http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8004132
>>>
>>>  http://cr.openjdk.java.net/~tamao/8004132/webrev.00/
>>>
>>>  Passed JPRT; I checked ValidateMarkSweep can't be triggered now with
>>>  the fix.
>>>
>>>  Background:
>>>
>>>  While verifying the functionality of the ValidateMarkSweep code with
>>>  the Serial collector (prior to adding code to enable this feature in
>>>  G1) Tao and myself saw various crashes and failures when running GC 
>>> Old.
>>>
>>>  Script to run GCOld:
>>>  #JHOME=/export/jdk8/solaris-x64
>>>  #JHOME=/java/re/jdk/6/promoted/latest/binaries/solaris-i586/fastdebug
>>>  JHOME=/export/bugs/8001047/jdk7/solaris-x64
>>>
>>>  $JHOME/bin/java -server -Xms1g -Xmx1g \
>>>          -XX:+UseSerialGC \
>>>          -XX:+ValidateMarkSweep \
>>>          -XX:+PrintGCDetails -XX:+PrintGCTimeStamps
>>>  -XX:+ShowMessageBoxOnError \
>>>                  GCOld 9000 20 5 30 500000
>>>
>>>  Note the ValidateMarkSweep functionality is only available in
>>>  non-product builds.
>>>
>>>  This seems to have been broken for a long while - we even saw the
>>>  crash with jdk6. Thus we suggest to remove the ValidateMarkSweep code.
>>>
>>
>