ParNew garbage collection

[Darji, Kinnari]

I am using jdk-1.6.0_16 version. Is there any known issue with this version?
Also I have tried +PrintSafepointStatistics option in past but it prints out time which does not actual correlate to the time. It is hard to match it up the occurrence of event. I will try with TraceSafepointCleanup option.

Thank you
Kinnari

From: hotspot-gc-use-bounces at openjdk.java.net [mailto:hotspot-gc-use-bounces at openjdk.java.net] On Behalf Of Srinivas Ramakrishna
Sent: Wednesday, January 04, 2012 12:54 PM
To: Jon Masamitsu
Cc: hotspot-gc-use at openjdk.java.net
Subject: Re: ParNew garbage collection

May be also +PrintSafepointStatistics (and related parms) to drill down a bit further, although TraceSafepointCleanup
would probably provide all of the info on a per-safepoint basis. There was an old issue wrt monitor
deflation that was foixed a few releases ago, so Kinnari should check the version of the JVM she's
running on as well.... (There are now a couple of flags related to monitor list handling policies i believe
but i have no experience with them and do not have the code in front of me -- make sure to cc the runtime
list if that turns out to be the issue again and you are already on a very recent version of the JVM.)

-- ramki
On Wed, Jan 4, 2012 at 9:43 AM, Jon Masamitsu <jon.masamitsu at oracle.com<mailto:jon.masamitsu at oracle.com>> wrote:
Try turning on TraceSafepointCleanupTime.  I haven't used it myself.  If
that's not it, look in share/vm/runtime/globals.hpp for some other flag
that traces safepoints.


On 1/3/2012 1:36 PM, Darji, Kinnari wrote:

Hello GC team,

I have question regarding ParNew collection. As in logs below, the GC is taking only 0.04 sec but application was stopped for 1.71 sec. What could possibly cause this? Please advise.



2012-01-03T14:37:04.975-0500: 30982.368: [GC 30982.368: [ParNew

Desired survivor size 19628032 bytes, new threshold 4 (max 4)

- age   1:    4466024 bytes,    4466024 total

- age   2:    3568136 bytes,    8034160 total

- age   3:    3559808 bytes,   11593968 total

- age   4:    1737520 bytes,   13331488 total

: 330991K->18683K(345024K), 0.0357400 secs] 5205809K->4894299K(26176064K), 0.0366240 secs] [Times: user=0.47 sys=0.04, real=0.04 secs]

Total time for which application threads were stopped: 1.7197830 seconds

Application time: 8.4134780 seconds







Thank you

Kinnari







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