RFR: Cleanup allocation tracking in heuristics

[Roman Kennke]

Even better!

On Fri, Mar 2, 2018 at 1:46 PM, Aleksey Shipilev <shade at redhat.com> wrote:
> On 03/02/2018 12:40 PM, Aleksey Shipilev wrote:
>> http://cr.openjdk.java.net/~shade/shenandoah/heuristics-bytes-allocated/webrev.01/
>>
>> This cleans up allocation tracking in heuristics. Most of the things are not used and bit-rotted
>> over the last year. The one thing that is still important to us -- bytes allocated since last cycle
>> -- is updated racily, and thus is unreliable.
>
> Actually, acquiring the ShHeapLock for resetting a single flag in ShConcThread is probably too
> excessive, as it has the potential to delay the first STW that dives into the cycle.
>
> Rewritten that with atomics:
>   http://cr.openjdk.java.net/~shade/shenandoah/heuristics-bytes-allocated/webrev.02/
>
> -Aleksey
>