Why abortable-preclean phase is not being aborted after YG occupancy exceeds 50%?

[Srinivas Ramakrishna]

Ah, I see. I'll go back and review your email on this subject earlier.
Sorry, got pulled off for some other stuff and missed the follow-ups.

thanks.
-- ramki

On Wed, Aug 22, 2012 at 4:40 AM, Frajt, Michal <
Michal.Frajt at partner.commerzbank.com> wrote:

> Hi Damon,
>
> It is not paging. The unpredictable delay from a scavenge to a CMS initial
> mark is the state of the current implementation. The CMSWaitDuration does
> not work correctly. Please find the details in the "CMSWaitDuration
> unstable behavior" post on hotspot-gc-dev mailing.
>
> We are facing same issue with extremely long initial mark pauses. Just
> proper waiting for a scavenge (customized OpenJDK 6) has reduced every
> single initial-mark pause from 1200ms to 20ms only.
>
> Regards,
> Michal
>
>
> -----Original Message-----
> From: hotspot-gc-use-bounces at openjdk.java.net [mailto:
> hotspot-gc-use-bounces at openjdk.java.net] On Behalf Of Damon Hart-Davis
> Sent: Mittwoch, 22. August 2012 11:31
> To: Srinivas Ramakrishna; Bernd Eckenfels
> Cc: hotspot-gc-use at openjdk.java.net
> Subject: Re: Why abortable-preclean phase is not being aborted after YG
> occupancy exceeds 50%?
>
> Hi,
>
> Could it be paging when not all of the JVM heap is (able to be) in
> physical memory at the same time?
>
> Rgds
>
> Damon
>
>
> On 22 Aug 2012, at 09:03, Srinivas Ramakrishna wrote:
>
> > I am not sure why, with regular CMS, we should have this kind of
> upredictable delay from a scavenge to a CMS initial mark.
> > It must be OS/scheduling and load etc. which we cannot control (although
> a delay of 177 s seems excessive and must either mean
> > that the CMS wait duration was exceeded or something like that.
>
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>
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