title: ParNew gc will stop the world?
body: <p>I see GC output like below:</p>
  
  <pre><code>2010-12-10T16:00:44.942+0800: 1443.562: [GC 1443.562: [ParNew: 201856K-&gt;17318K(201856K), 0.0352970 secs] 2113334K-&gt;1949037K(4416748K) icms_dc=0 , 0.0354310 secs] [Times: user=0.12 sys=0.00, real=0.04 secs]
  2010-12-10T16:00:46.207+0800: 1444.827: [GC 1444.827: [ParNew: 196774K-&gt;22400K(201856K), 0.0119290 secs] 2128493K-&gt;1954446K(4416748K) icms_dc=0 , 0.0120560 secs] [Times: user=0.13 sys=0.00, real=0.02 secs]
  2010-12-10T16:00:47.562+0800: 1446.182: [GC 1446.182: [ParNew: 201856K-&gt;22400K(201856K), 0.0714350 secs] 2133902K-&gt;1982695K(4416748K) icms_dc=0 , 0.0715720 secs] [Times: user=0.23 sys=0.01, real=0.07 secs]
  2010-12-10T16:00:48.545+0800: 1447.165: [GC 1447.165: [ParNew: 201856K-&gt;22400K(201856K), 0.1457230 secs] 2162151K-&gt;2008418K(4416748K) icms_dc=0 , 0.1458710 secs] [Times: user=0.71 sys=0.05, real=0.15 secs]
  </code></pre>
  
  <p>I want to know if ParNew GC will stop all threads. Thanks.</p>