hotspot-gc-use Digest, Vol 46, Issue 9

Jon Masamitsu jon.masamitsu at oracle.com
Thu Dec 29 14:28:24 UTC 2011


This is close to the CMS flag but is a percent of
the entire heap (as opposed to the tenured
generation for CMS).

-XX:InitiatingHeapOccupancyPercent=NN

On 12/29/11 01:45, Guy Korland wrote:
> Yes, I'm familiar with this configuration for CMS.
> Is there a similar configuration for G1?
>
> Thanks,
> Guy
>
>
> On Thu, Dec 29, 2011 at 1:32 AM, Jon Masamitsu 
> <jon.masamitsu at oracle.com <mailto:jon.masamitsu at oracle.com>> wrote:
>
>
>
>     On 12/28/2011 1:17 PM, Guy Korland wrote:
>
>         Thanks for the answer, is there any chance you can also help
>         with my other
>         question?
>         Is there a way with as with cms to control the "occupancy"?
>
>
>     If you mean the occupancy at which CMS starts  a collection, try
>     -XX:CMSInitiatingOccupancyFraction=NN where NN is the
>     percentage of the tenured generation at which a CMS collection
>     will start.
>
>     If you mean something else, please ask again.
>
>
>         Thanks,
>         Guy
>
>
>             ---
>             Date: Tue, 27 Dec 2011 14:06:53 -0800
>             From: Jon Masamitsu<jon.masamitsu at oracle.com
>             <mailto:jon.masamitsu at oracle.com>>
>             Subject: Re: Turning off generational GC
>             To: hotspot-gc-use at openjdk.java.net
>             <mailto:hotspot-gc-use at openjdk.java.net>
>             Message-ID:<4EFA417D.4070009 at oracle.com
>             <mailto:4EFA417D.4070009 at oracle.com>>
>             Content-Type: text/plain; charset="iso-8859-1"
>
>             For the hotspot garbage collectors the short answer is
>             "no" there is no
>             way to
>             turn off generational GC.  I think it's even pretty deeply
>             entrenched in
>             G1 which
>             is only logically generational.
>
>             If CMS were not generational, in the best cause you would
>             see pauses
>             on the order of 20ms.  Maybe much larger although less
>             frequent.
>             More likely would be concurrent mode failures which would
>             lead to
>             full GC's.
>
>
>             On 12/27/2011 1:20 PM, Guy Korland wrote:
>
>                 Hi,
>
>                 I hope this is the right forum for this.
>                 It seems like no matter how small we set the young
>                 generation, it take
>
>         more
>
>                 than 20ms.
>                 Is there a way turn off generational GC, especially in
>                 CMS?
>
>                 Thanks,
>                 Guy
>
>
>
>                 _______________________________________________
>                 hotspot-gc-use mailing list
>                 hotspot-gc-use at openjdk.java.net
>                 <mailto:hotspot-gc-use at openjdk.java.net>
>                 http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use
>
>             -------------- next part --------------
>             An HTML attachment was scrubbed...
>             URL:
>
>         http://mail.openjdk.java.net/pipermail/hotspot-gc-use/attachments/20111227/99fc1a6a/attachment-0001.html
>
>             ------------------------------
>
>             _______________________________________________
>             hotspot-gc-use mailing list
>             hotspot-gc-use at openjdk.java.net
>             <mailto:hotspot-gc-use at openjdk.java.net>
>             http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use
>
>
>             End of hotspot-gc-use Digest, Vol 46, Issue 9
>             *********************************************
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.openjdk.java.net/pipermail/hotspot-gc-dev/attachments/20111229/6687e6c0/attachment.htm>
-------------- next part --------------
_______________________________________________
hotspot-gc-use mailing list
hotspot-gc-use at openjdk.java.net
http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use


More information about the hotspot-gc-dev mailing list