RFR(xxs): 8199432: metaspace: fix wrong comment and condition in SpaceManager::verify()

[coleen.phillimore at oracle.com]

This looks good and potentially trivial.

Coleen

On 3/12/18 3:23 AM, Thomas Stüfe wrote:
> Hi all,
>
> may I please have sponsor/reviewers for this tiny fix:
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8199432
> webrev: http://cr.openjdk.java.net/~stuefe/webrevs/8199432-fix-spacemanager-
> verify/webrev.00/webrev/
>
> Basically, the condition and the comment make no sense anymore.
>
> They used to make sense: in an earlier version of the Metaspace ("6964458:
> Reimplement class meta-data storage to use native memory") the Metablocks
> inside a metachunk always had headers and therefore were walkable. So,
> Metachunk::verify walked all the blocks - which was not possible if were
> returned with Metaspace::deallocate() and added to the block dictionary.
>
> This is not true anymore, now MetaBlocks generally do not have a header, so
> MetaChunk::verify() does not walk them and is generally oblivious to
> anything happening in the MetaChunk payload area. So, one can now always
> call MetaChunk::verify(), regardless if MetaBlocks are in the block
> dictionary or not.
>
>
> Thanks, Thomas