Deferral justification: JDK-8022892
tao.mao at oracle.com
Thu Aug 15 01:53:41 UTC 2013
Hi GC team,
The CR is here https://jbs.oracle.com/bugs/browse/JDK-8022892.
First of all, Jon pointed out it's not a regression in hs24 since it
reported against hs23. (Thank you, Jon) I think this is right. But i'm
not sure, only with that, whether I can get through the deferral process.
So, let me put down what I have found so far.
1. In the CR, Exception Code:c0000005 is seen and it means
EXCEPTION_ACCESS_VIOLATION. This type of error is reported many times in
different places inside and outside VM. Also, in the CR, it shows "
Fault Module Name:msvcr100.dll", which indicates the top of stack frame
is C native code/3rd party library from Microsoft. Thus, it may be not a
VM problem at all, in this case.
2. Let's look at the ILW priority mapping. The impact is high since it's
But there's ambiguity about its likelihood and workaround. I would think
the likelihood is low according to the definition
" The defect is encountered in an uncommon (or unsupported) use case or
is intermittent in nature with a low frequency of occurrence"
Starting with initial heap size 140GB seems to be an uncommon use case
Workaround: use other collector as the report stated or lower heap size.
ILW = HLL = P4.
3. In fact, it's hard to find a windows machine configured with 140GB
memory. Probably there's no such machine if you refer to RAM/CPU limits
of Windows machine stated in Microsoft website
(http://support.microsoft.com/kb/2860880). The RAM limit for Windows HPC
Server 2008 R2 is 128GB. That's the reason why I think the likelihood is
What I'm trying to do here is to use the Linux machine
sthdev05.se.oracle.com listed here
machine have about 256GB memory. But the VM cannot allocate(commit)
enough memory if I set -Xms to be 35g or higher. In this attempt, we are
not yet close to reproducing.
Ok, that's all I've found.
Among all these, I'd like to add the 128GB RAM limit of this type of
Windows server as the second justification.
Could you read the email and look through the bug report to help obtain
at least one more evidence for the deferral justification if possible?
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