JDK-6896624 : G1: hotspot:::gc and hotspot:::mem-pool-gc probes are not fired
  • Type: Bug
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: hs14
  • Priority: P3
  • Status: Closed
  • Resolution: Fixed
  • OS: solaris
  • CPU: generic
  • Submitted: 2009-10-30
  • Updated: 2013-09-18
  • Resolved: 2011-03-08
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JDK 6 JDK 7 Other
6u25Fixed 7Fixed hs20Fixed
Related Reports
Relates :  
JDK-6941275 - G1: The MemoryPools are incorrectly supported for G1
Relates :  
JDK-6458402 - 3 jvmti tests fail with CMS and +ExplicitGCInvokesConcurrent
Relates :  
JDK-7009379 - G1: Dtrace probes in G1 are not correct
Description
The following probes are not fired in case G1 is used:
 hotspot:::gc-begin
 hotspot:::gc-end
 hotspot:::mem-pool-gc-begin
 hotspot:::mem-pool-gc-end

The probes are not fired for both client and server compiler, on all solaris platforms.
Comments
EVALUATION http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/7c5250dbd584
20-12-2010
SUGGESTED FIX Additional note: in a departure from what's done before I'm going to call the probes from the methods that actually do the collection, not the VM operations that schedule the collection, given that the former is a more reliable way to ensure that when a probe fires the collection will indeed happen (i.e., a VM operation that's supposed to do a collection might not if say the GC locker is active).
17-12-2010
SUGGESTED FIX Call notify_gc_begin() / notify_gc_end() from the G1 VM Operations.
17-12-2010
EVALUATION The memory pool probes are fired by G1. Most likely the introduction of the G1 memory pools as part of 6941275: G1: The MemoryPools are incorrectly supported for G1 ensured that. So, we only seem to be missing the gc-begin / gc-end probes.
17-12-2010
EVALUATION The reason for the missing hotspot:::gc probes is that we don't call VM_GC_Operation::notify_gc_begin() / notify_gc_end() methods from the G1 VM operations. Looking at the memory poo probes next.
17-12-2010