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: 6463133
Votes 0
Synopsis Deoptimization should not use code patching
Category hotspot:compiler2
Reported Against
Release Fixed hs10(b06), 6u4(b03) (Bug ID:2171816) , 7(b06) (Bug ID:2176812)
State 10-Fix Delivered, request for enhancement
Priority: 4-Low
Related Bugs 6507028 , 6511756 , 6603919 , 6669441 , 6670173
Submit Date 23-AUG-2006
Description
Deoptimization is susceptible to failure because it uses cross code patching. At the moment we know of no cpu's where this fails but we may well be running out of time. Newer  customer  processors have an errata which isn't planned to be fixed that hints that we could fail.

We should use a deopt scheme that uses return address patching instead. This also allows us to go to single frame deopt. a capability we lost when lazy deopt was implemented.
Posted Date : 2006-08-23 16:53:25.0
Work Around
N/A
Evaluation
From the putback comment:

This converts deoptimization to no longer do patching of code
and now only patches return address. This made a rather large
change to the frame object so that now a frame always carries
along the codeBlob it refers to if it in fact does refer to
a codeBlob. This removes lots of redundant CodeCache::find_blob
calls. The testing of this fix which obviously changes the way
frames look on the stack discovered that both SA and pstack support
have been broken. pstack support has been been broken for years.
Posted Date : 2007-01-17 21:11:09.0
Comments
  
  Include a link with my name & email   


PLEASE NOTE: JDK6 is formerly known as Project Mustang