Java Solaris Communities Sun Store Join SDN My Profile Why Join?
 
Bug Database
Bug Detail
Quick Lists
Top 25 Bugs
Top 25 RFE's
Recently Closed Bugs
Printable Page Printable Page


Bug Database
Bug ID: 6850846
Votes 0
Synopsis G1: extend G1 marking verification
Category hotspot:garbage_collector
Reported Against
Release Fixed hs16(b05), 7(b63) (Bug ID:2179586)
State 10-Fix Delivered, request for enhancement
Priority: 4-Low
Related Bugs
Submit Date 12-JUN-2009
Description
G1 uses two different versions of the marking information:

- "prev" is the last one completed (which is guaranteed to be consistent and complete, i.e., no live  customer  should be pointing to a dead  customer , but maybe no up-to-date) and
- "next" is the marking information that is being computed next (and which might be incomplete, as we might be half-way through completing it)

Heap verification in G1 also checks the consistency of the "prev" marking information (given that it's the only marking information that we can trust to be complete). However, we would also like to check the consistency of the "next" marking information at the only place where we can, which is the end of the remark phase. 

This CR proposes to change the G1 verification code to either use the "prev" or "next" marking info, depending on what the caller needs.

Additionally, it adds verification of the "next" marking info at the end of the remark (conditional on the VerifyDuringGC flag) and removes the #ifndef PRODUCT from the verification at the end of cleanup (it's  customer  to be able to do heap / marking verification in a product build).
Posted Date : 2009-06-12 19:28:49.0
Work Around
N/A
Evaluation
See Description.
Posted Date : 2009-06-12 19:29:24.0

http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/830ca2573896
Posted Date : 2009-06-19 13:56:28.0
Comments
  
  Include a link with my name & email   


PLEASE NOTE: JDK6 is formerly known as Project Mustang