RFR(S): 7194633: G1: Assertion and guarantee failures in block offset table

[Bengt Rutisson]

Ship it!

Bengt


On 2012-11-27 20:15, John Cuthbertson wrote:
> Hi Ramki, Bengt,
>
> Thanks for the reviews. I've changed the added messages to include 
> whitespace around the format macros.
>
> Regards,
>
> JohnC
>
> On 11/21/12 00:26, Bengt Rutisson wrote:
>>
>> Looks good to me too.
>>
>> I like that you introduced the check_index() and check_offset() methods.
>>
>> One style question. You are using the format macros without white 
>> spaces. After grepping a bit in the hotspot source I think it is more 
>> common to have white spaces when using these. So instead of 
>> "..."SIZE_FORMAT"..", "..."UINT32_FORMAT"..." etc I think it would be 
>> more hotspot-like to use "..." SIZE_FORMAT "..." and "..." 
>> UINT32_FORMAT "...".
>>
>> Bengt
>>
>>
>> On 2012-11-21 02:40, Srinivas Ramakrishna wrote:
>>> Looks good to me.
>>>
>>> -- ramki
>>>
>>> On Tue, Nov 20, 2012 at 4:57 PM, John Cuthbertson <
>>> john.cuthbertson at oracle.com> wrote:
>>>
>>>> Hi Everyone,
>>>>
>>>> Can I have a couple of volunteers review the changes at:
>>>> http://cr.openjdk.java.net/~**johnc/7194633/webrev.0<http://cr.openjdk.java.net/%7Ejohnc/7194633/webrev.0>? 
>>>>
>>>>
>>>> Background:
>>>>
>>>> While I was testing the fix for 719066 I ran into several 
>>>> assertions and
>>>> guarantee failures from G1's block offset table when running 
>>>> through jprt.
>>>> The failures were associated with using a specific version of the 
>>>> sparc
>>>> memset to initialize the offsets array (see 7192128) which was 
>>>> missing from
>>>> my 7190666 workspace. The changes in this webrev are the 
>>>> instrumenation and
>>>> detailed error message changes I made to verify that G1's block offset
>>>> table was not immune to the memset issue and that the failures from 
>>>> jprt
>>>> were the same issue. These detailed error messages were invaluable 
>>>> when
>>>> tracking the issue down.
>>>>
>>>> Testing:
>>>> GCBasher with -UseMemsetInBOT on sparc
>>>> Forcibly triggering the failures to check that the error messages made
>>>> sense.
>>>> jprt
>>>>
>>>> It is still my intent to merge G1's BOT with that of the other 
>>>> collectors
>>>> and remove the large amount of duplicated code (which is a separate 
>>>> CR).
>>>> When I do that, the detailed error messages will be included in the 
>>>> shared
>>>> BOT code.
>>>>
>>>> Thanks,
>>>>
>>>> JohnC
>>>>
>>
>