[11u] Backport JEP 346 : Promptly Return Unused Committed Memory from G1

[Thomas Stüfe]

Hi,

I am a bit concerned about this.

We are in the process of gently nudging our internal customers up to jdk 11
from jdk 8. We are also internally providing an "11ified" jdk 8, similar to
the old hotspot express model. So hotspot 11 gets used alot in our company
and in a lot of very different scenarios. Elasticity is welcome, but any
destabilization of G1 would be catastrophic.

As a counter example, the Shenandoah backport makes me feel less
apprehensive since I know that RedHat has a strong commitment to backport
releases and that the Shenandoah developers work focused on Shenandoah in
the main line (so their resources are not split between different GCs). I'd
feel safer if I had a similar commitment from Oracle G1 developers about
backing this backport. Do we have that (I may have missed this)?

And as Aleksey wrote in his initial review, a killswitch - where "off" is a
reliably tested scenario - would be good.

Thanks, Thomas

On Mon, Oct 12, 2020 at 11:36 AM Andrew Haley <aph at redhat.com> wrote:

> On 12/10/2020 09:02, Ruslan Synytsky wrote:
> > Dear Liang, thank you for the extra efforts on this improvement.
> >
> > Dear Andrew, I assume we need your approval / confirmation. Can you
> please take a look and let us know your feedback?
>
> OK, I'll have a look and get some input from others.
>
> --
> Andrew Haley  (he/him)
> Java Platform Lead Engineer
> Red Hat UK Ltd. <https://www.redhat.com>
> https://keybase.io/andrewhaley
> EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671
>
>