RFR: Add support for CollectedHeap::get_safepoint_workers()

[Ramki Ramakrishna]

Hi Per,

is there a bug id that you can link to the webrev for background (for those
who came in late)?

thanks!
-- ramki (openjdk: ysr)

On Tue, May 8, 2018 at 7:49 AM, Per Liden <per.liden at oracle.com> wrote:

> Added support for CollectedHeap::get_safepoint_workers(), to reduce
> safepoint cleanup times.
>
> http://cr.openjdk.java.net/~pliden/zgc/get_safepoint_workers/webrev.0
>
> Here are some numbers on from SPECjbb2015, which look encouraging.
>
> Before:
>
> Safepoint cleanup tasks (secs):
>                 avg: 0.00286622 (+/-0.00189263)
>     95th percentile: 0.0059704
>     99th percentile: 0.006819
>   99.9th percentile: 0.0089186
>  99.99th percentile: 0.0117573
>                 max: 0.0117573
>
> After:
>
> Safepoint cleanup tasks (secs):
>                 avg: 0.000676487 (+/-0.000212009)
>     95th percentile: 0.0010262
>     99th percentile: 0.0011429
>   99.9th percentile: 0.0012933
>  99.99th percentile: 0.0013363
>                 max: 0.0013363
>
> /Per
>



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