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

[Srinivas Ramakrishna]

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
>