<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Leon,<br>
<br>
In this log you see as part of an entry "PSOldGen:" which says
you're<br>
using the serial mark sweep. I see in your later posts that
"ParOldGen:"<br>
appears in your log and that is the parallel mark sweep collector.<br>
<br>
Jon<br>
<br>
On 4/18/2012 1:58 AM, <a class="moz-txt-link-abbreviated" href="mailto:the.6th.month@gmail.com">the.6th.month@gmail.com</a> wrote:
<blockquote
cite="mid:CAKzy53mXkLAb81UH-zhaowMyQtEsFHP7XV9GpShsRzjCvh3HBA@mail.gmail.com"
type="cite">
<pre wrap="">Hi, Simon:
this is the full gc log for your concern.
2012-04-18T16:47:24.824+0800: 988.392: [GC
Desired survivor size 14876672 bytes, new threshold 1 (max 15)
[PSYoungGen: 236288K->8126K(247616K)] 4054802K->3830711K(4081472K),
0.0512250 secs] [Times: user=0.15 sys=0.00, real=0.05 secs]
2012-04-18T16:47:24.875+0800: 988.443: [Full GC [PSYoungGen:
8126K->0K(247616K)] [PSOldGen: 3822585K->1751429K(3833856K)]
3830711K->1751429K(4081472K) [PSPermGen: 81721K->81721K(262144K)],
6.6108630 secs] [Times: user=6.62 sys=0.00, real=6.61 secs]
the full gc time is almost unchanged since I enabled paralleloldgc.
Do you have any recommendation for an appropriate young gen size?
Thanks
All the best,
Leon
On 18 April 2012 16:24, Simone Bordet <a class="moz-txt-link-rfc2396E" href="mailto:sbordet@intalio.com"><sbordet@intalio.com></a> wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Hi,
On Wed, Apr 18, 2012 at 10:16, <a class="moz-txt-link-abbreviated" href="mailto:the.6th.month@gmail.com">the.6th.month@gmail.com</a>
<a class="moz-txt-link-rfc2396E" href="mailto:the.6th.month@gmail.com"><the.6th.month@gmail.com></a> wrote:
</pre>
<blockquote type="cite">
<pre wrap="">hi all:
I'm currently using jdk 6u26. I just enabled UseParallelOldGC, expecting
that would enhance the full gc efficiency and decrease the mark-sweep
</pre>
</blockquote>
<pre wrap="">time
</pre>
<blockquote type="cite">
<pre wrap="">by using multiple-core. The JAVA_OPTS is as below:
-XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintTenuringDistribution
-Xloggc:gc.log-server -Xms4000m -Xmx4000m -Xss256k -Xmn256m
-XX:PermSize=256m -XX:+UseParallelOldGC -server
-Dorg.apache.jasper.compiler.Parser.STRICT_QUOTE_ESCAPING=false
as shown in jinfo output, the settings have taken effect, and the
ParallelGCThreads is 4 since the jvm is running on a four-core server.
But what's strange is that the mark-sweep time remains almost unchanged
</pre>
</blockquote>
<pre wrap="">(at
</pre>
<blockquote type="cite">
<pre wrap="">around 6-8 seconds), do I miss something here? Does anyone have the same
experience or any idea about the reason behind?
Thanks very much for help
</pre>
</blockquote>
<pre wrap="">
The young generation is fairly small for a 4GiB heap.
Can we see the lines you mention from the logs ?
Simon
--
<a class="moz-txt-link-freetext" href="http://cometd.org">http://cometd.org</a>
<a class="moz-txt-link-freetext" href="http://intalio.com">http://intalio.com</a>
<a class="moz-txt-link-freetext" href="http://bordet.blogspot.com">http://bordet.blogspot.com</a>
----
Finally, no matter how good the architecture and design are,
to deliver bug-free software with optimal performance and reliability,
the implementation technique must be flawless. Victoria Livschitz
_______________________________________________
hotspot-gc-use mailing list
<a class="moz-txt-link-abbreviated" href="mailto:hotspot-gc-use@openjdk.java.net">hotspot-gc-use@openjdk.java.net</a>
<a class="moz-txt-link-freetext" href="http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use">http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use</a>
</pre>
</blockquote>
<pre wrap="">
</pre>
<pre wrap="">
<fieldset class="mimeAttachmentHeader"></fieldset>
_______________________________________________
hotspot-gc-use mailing list
<a class="moz-txt-link-abbreviated" href="mailto:hotspot-gc-use@openjdk.java.net">hotspot-gc-use@openjdk.java.net</a>
<a class="moz-txt-link-freetext" href="http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use">http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use</a>
</pre>
</blockquote>
</body>
</html>