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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 class="moz-cite-prefix">On 09/07/2012 10:17 AM, Dmytro Sheyko
wrote:<br>
</div>
<blockquote cite="mid:SNT137-W1FAD76A99BBBD6A05D9028AAF0@phx.gbl"
type="cite">
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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 class="moz-signature" cols="72">--
Azeem Jiva
@javawithjiva</pre>
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