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Hi Tony,<br>
<br>
I hope I am not too late in providing feedback on this change. Here
are couple of suggestions for the heap regions information in hs_err
file:<br>
<br>
- I think it would be useful to print a header before the heap
regions details. e.g.<br>
<br>
Heap<br>
garbage-first heap total 20480K, used 11630K [0x6e600000,
0x6fa00000, 0xae600000)<br>
region size 1024K, 1 young (1024K), 1 survivors (1024K)<br>
compacting perm gen total 16384K, used 2604K [0xae600000,
0xaf600000, 0xb2600000)<br>
the space 16384K, 15% used [0xae600000, 0xae88b3c0, 0xae88b400,
0xaf600000)<br>
No shared spaces configured.<br>
<br>
<b>Heap Regions:</b><br>
0 PTAMS 0x6e600000 NTAMS 0x6e639700 space 1024K,
22% used [0x6e600000, 0x6e639700, 0x6e700000)<br>
F 17 PTAMS 0x6e700000 NTAMS 0x6e700000 space 1024K,
0% used [0x6e700000, 0x6e700000, 0x6e800000)<br>
F 17 PTAMS 0x6e800000 NTAMS 0x6e800000 space 1024K,
0% used [0x6e800000, 0x6e800000, 0x6e900000)<br>
<br>
<br>
- Also, I think it would be helpful for the hs_err file reader to
have the meanings of the acronyms also printed (as we show in the
stack trace in hs_err file)<br>
<br>
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code,
C=native code)<br>
V [libjvm.so+0xc494db] VMError::report_and_die()+0x19b<br>
<br>
Heap Regions: (CS=collection set, PTAMS=previous top at mark start,
NTAMS=next top at mark start, etc...)<br>
17 PTAMS 0x6f200000 NTAMS 0x6f300000 space 1024K,
100% used [0x6f200000, 0x6f300000, 0x6f300000)<br>
CS SU 17 PTAMS 0x6f300000 NTAMS 0x6f38e650 space 1024K,
55% used [0x6f300000, 0x6f38e650, 0x6f400000)<br>
17 PTAMS 0x6f400000 NTAMS 0x6f493c60 space 1024K,
57% used [0x6f400000, 0x6f493c60, 0x6f500000)<br>
<br>
<br>
<br>
Thanks,<br>
Poonam<br>
<br>
<br>
On 10/12/2011 10:19 PM, Tony Printezis wrote:
<blockquote cite="mid:4E95C529.3070909@oracle.com" type="cite">Hi
all,
<br>
<br>
(I'm also copying the runtime alias, as this change will concern
them too)
<br>
<br>
I'd like to get a couple of reviews for this change:
<br>
<br>
<a class="moz-txt-link-freetext" href="http://cr.openjdk.java.net/~tonyp/7099849/webrev.0/">http://cr.openjdk.java.net/~tonyp/7099849/webrev.0/</a>
<br>
<br>
Some background: when trying to track down issues in G1 it is
often very helpful to know what type of regions the heap has
and/or get information on a particular region (whether it's
humongous, whether it's young, how full it is, etc.). We thought
it'd be a good idea to include the per-region information in the
hs_err file to always have it available after a crash.
<br>
<br>
I don't think the changes in the webrev are too controversial. The
reason I wanted to give a heads up to both groups was to point out
that this change will increase the size of the hs_err files when
G1 is used. It's common to have 1,000 to 2,000 regions in the
heap, if larger heaps are used (much fewer if smaller heaps are
used), which means that the hs_err file will have this many extra
lines. Does anyone have any concerns about this?
<br>
<br>
I attached an example hs_err file obtained from a workspace with
this change applied.
<br>
<br>
BTW, I also cleaned up a bit the way the print() methods on the
heap are defined (I pushed the default behavior to the superclass,
where possible).
<br>
<br>
Tony
<br>
<br>
</blockquote>
<br>
<div class="moz-signature">-- <br>
Best regards, Poonam
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