RFR: JDK-8260200: optimize FreeRegionList::remove_starting_at by removing u… [v2]

[Albert Mingkun Yang]

On Fri, 22 Jan 2021 01:38:11 GMT, Hamlin Li <mli at openjdk.org> wrote:

>> optimize FreeRegionList::remove_starting_at by removing unnecessary reading and setting
>> 
>> FreeRegionList::remove_starting_at(...) traverses from a node and removes subsequent N nodes from free list. But when traverses the free list, it removes nodes one by one by setting the prev and next pointers of prev and next node. it's not necessary do these settings for every node, as we can remove target nodes at once and just set prev and next pointers for just 2 nodes.
>
> Hamlin Li has updated the pull request incrementally with one additional commit since the last revision:
> 
>   JDK-8260200: optimize FreeRegionList::remove_starting_at by removing unnecessary reading and setting

Thanks for the revision.

I think the doc on `next` can be further improved. It's best to describe its purpose, sth like, after  the while-loop, `next` should point to the next node right after the removed sublist, or null if the sublist contains tail.

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Marked as reviewed by ayang (Author).

PR: https://git.openjdk.java.net/jdk/pull/2181