<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
I had not thought about other processes, which is a possibility.
Although raising the priority of the GC threads won't help which I
believe what Dmytro was suggestion.<br>
<br>
<br>
<div class="moz-cite-prefix">On 09/07/2012 10:35 AM, Vitaly
Davidovich wrote:<br>
</div>
<blockquote
cite="mid:CAHjP37FdfK=0DPOzyRS-FzzOS_JmthzMZWOEjCH3bFJXqOeo0g@mail.gmail.com"
type="cite">
<p>You can have other threads from different processes in the
system competing though.</p>
<p>However, such a large wall time vs CPU time can also be caused
by heavy swapping on a slow disk. The heap there doesn't look
all that big though ...</p>
<p>Sent from my phone</p>
<div class="gmail_quote">On Sep 7, 2012 11:21 AM, "Azeem Jiva"
<<a moz-do-not-send="true"
href="mailto:azeem.jiva@oracle.com">azeem.jiva@oracle.com</a>>
wrote:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"> The Parallel collector
is a stop-the-world collector. The Java threads are
suspended until the GC finishes. I think your survivor
spaces maybe mis-configured, and that's why you're seeing
such large GC times. <br>
<br>
<br>
<div>On 09/07/2012 10:17 AM, Dmytro Sheyko wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr"> Hi,<br>
<br>
I can see that Parallel GC works on threads with
NormPriority, while CMS and G1 threads run with
NearMaxPriority. This probably not an issue if java
application works alone, but some time ago I observed GC
log like this (it was Jenkins CI on Windows):<br>
<br>
[Full GC [PSYoungGen: 10352K->0K(171904K)] [PSOldGen:
403417K->114637K(415872K)]
413769K->114637K(587776K) [PSPermGen:
76315K->76315K(83968K)], 30.2595731 secs] [Times:
user=0.77 sys=0.41, real=30.26 secs]<br>
<br>
Despite cpu time for GC was just 1.18 sec (= 0.77 +
0.41), the real time was 30.26 sec! It seems to me that
the system was busy that time and GC threads was
starving.<br>
<br>
If we could raise priority of Parallel GC threads, other
application would have less impact on GC duration.<br>
<br>
What do you think?<br>
<br>
Thanks,<br>
Dmytro </div>
</blockquote>
<br>
<pre cols="72">--
Azeem Jiva
@javawithjiva</pre>
</div>
</blockquote>
</div>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Azeem Jiva
@javawithjiva</pre>
</body>
</html>