CRR (S): 7099849: G1: include heap region information in hs_err files

poonam.bajaj at oracle.com poonam.bajaj at oracle.com
Fri Nov 4 18:50:16 UTC 2011


On 11/4/2011 8:47 PM, Tony Printezis wrote:
> Poonam, I removed the notion of "GC alloc region" with 7039627. Are 
> you looking at a recent workspace?
>
Oh..ok. No, I was looking at the jdk7 hotspot and not the latest one. 
So, please ignore that comment, and the changes look fine to me.

regards,
Poonam

> Tony
>
> On 11/3/2011 8:38 PM, poonam.bajaj at oracle.com wrote:
>> Hi Tony,
>>
>> The changes and the output looks good!
>>
>> I noticed in heapRegion.cpp (in HeapRegion::print() ) that 'A' for GC 
>> Alloc region can also appear in the HeapRegion output, so would be 
>> good to add the meaning of A too in the header.
>>
>> Thanks,
>> Poonam
>>
>>
>> On 11/3/2011 9:57 PM, Tony Printezis wrote:
>>> Poonam,
>>>
>>> Latest webrev is here:
>>>
>>> http://cr.openjdk.java.net/~tonyp/7099849/webrev.1/webrev.all/
>>>
>>> This is what I changed compared to the previous one:
>>>
>>> http://cr.openjdk.java.net/~tonyp/7099849/webrev.1/webrev.1.G1HSErrExtra/
>>>
>>> I decided to also add "TS" before the GC time stamp on every line so 
>>> that I can describe what that that value is. (universe.hpp has the 
>>> white space changes Bengt asked for)
>>>
>>> This is some example output:
>>>
>>> Heap
>>>  garbage-first heap   total 32768K, used 21540K [0xace00000, 
>>> 0xaee00000, 0xaee00
>>> 000)
>>>   region size 1024K, 4 young (4096K), 2 survivors (2048K)
>>>  compacting perm gen  total 16384K, used 2663K [0xaee00000, 
>>> 0xafe00000, 0xb2e000
>>> 00)
>>>    the space 16384K,  16% used [0xaee00000, 0xaf099fe8, 0xaf09a000, 
>>> 0xafe00000)
>>> No shared spaces configured.
>>>
>>> Heap Regions: (Y=young(eden), SU=young(survivor), 
>>> HS=humongous(starts), HC=humongous(continues), CS=collection set, 
>>> F=free, TS=gc time stamp, PTAMS=previous top-at-mark-start, 
>>> NTAMS=next top-at-mark-start)
>>>           F TS    17 PTAMS 0xace00000 NTAMS 0xace00000 space 
>>> 1024K,   0% used [0xace00000, 0xace00000, 0xacf00000)
>>>             TS    11 PTAMS 0xacf00000 NTAMS 0xad000000 space 1024K, 
>>> 100% used [0
>>> ...
>>>
>>> and I also attached the full hs_err file.
>>>
>>> Better?
>>>
>>> Tony
>>>
>>> On 11/01/2011 10:08 AM, poonam.bajaj at oracle.com wrote:
>>>> Hi Tony,
>>>>
>>>> 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:
>>>>
>>>> - I think it would be useful to print a header before the heap 
>>>> regions details. e.g.
>>>>
>>>> Heap
>>>>  garbage-first heap   total 20480K, used 11630K [0x6e600000, 
>>>> 0x6fa00000, 0xae600000)
>>>>   region size 1024K, 1 young (1024K), 1 survivors (1024K)
>>>>  compacting perm gen  total 16384K, used 2604K [0xae600000, 
>>>> 0xaf600000, 0xb2600000)
>>>>    the space 16384K,  15% used [0xae600000, 0xae88b3c0, 0xae88b400, 
>>>> 0xaf600000)
>>>> No shared spaces configured.
>>>>
>>>> *Heap Regions:*
>>>>                   0 PTAMS 0x6e600000 NTAMS 0x6e639700 space 1024K,  
>>>> 22% used [0x6e600000, 0x6e639700, 0x6e700000)
>>>>           F    17 PTAMS 0x6e700000 NTAMS 0x6e700000 space 1024K,   
>>>> 0% used [0x6e700000, 0x6e700000, 0x6e800000)
>>>>           F    17 PTAMS 0x6e800000 NTAMS 0x6e800000 space 1024K,   
>>>> 0% used [0x6e800000, 0x6e800000, 0x6e900000)
>>>>
>>>>
>>>> - 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)
>>>>
>>>> Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, 
>>>> C=native code)
>>>> V  [libjvm.so+0xc494db]  VMError::report_and_die()+0x19b
>>>>
>>>> Heap Regions: (CS=collection set, PTAMS=previous top at mark start, 
>>>> NTAMS=next top at mark start, etc...)
>>>>                17 PTAMS 0x6f200000 NTAMS 0x6f300000 space 1024K, 
>>>> 100% used [0x6f200000, 0x6f300000, 0x6f300000)
>>>>     CS SU      17 PTAMS 0x6f300000 NTAMS 0x6f38e650 space 1024K,  
>>>> 55% used [0x6f300000, 0x6f38e650, 0x6f400000)
>>>>                17 PTAMS 0x6f400000 NTAMS 0x6f493c60 space 1024K,  
>>>> 57% used [0x6f400000, 0x6f493c60, 0x6f500000)
>>>>
>>>>
>>>>
>>>> Thanks,
>>>> Poonam
>>>>
>>>>
>>>> On 10/12/2011 10:19 PM, Tony Printezis wrote:
>>>>> Hi all,
>>>>>
>>>>> (I'm also copying the runtime alias, as this change will concern 
>>>>> them too)
>>>>>
>>>>> I'd like to get a couple of reviews for this change:
>>>>>
>>>>> http://cr.openjdk.java.net/~tonyp/7099849/webrev.0/
>>>>>
>>>>> 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.
>>>>>
>>>>> 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?
>>>>>
>>>>> I attached an example hs_err file obtained from a workspace with 
>>>>> this change applied.
>>>>>
>>>>> 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).
>>>>>
>>>>> Tony
>>>>>
>>>>
>>>> -- 
>>>> Best regards, Poonam
>>>>
>>>> Oracle <http://www.oracle.com>
>>>> Poonam Bajaj | Principal Member of Technical Staff
>>>> Phone: +91 80 66937451 <tel:+91%2080%2066937451> | Mobile: +91 
>>>> 9844511366 <tel:+91%209844511366>
>>>> Oracle JVM Sustaining Engineering
>>>>
>>>> ORACLE India Bangalore
>>>> Green Oracle <http://www.oracle.com/commitment> Oracle is committed 
>>>> to developing practices and products that help protect the environment
>>>>
>>
>> -- 
>> Best regards, Poonam
>>
>> Oracle <http://www.oracle.com>
>> Poonam Bajaj | Principal Member of Technical Staff
>> Phone: +91 80 66937451 <tel:+91%2080%2066937451> | Mobile: +91 
>> 9844511366 <tel:+91%209844511366>
>> Oracle JVM Sustaining Engineering
>>
>> ORACLE India Bangalore
>> Green Oracle <http://www.oracle.com/commitment> Oracle is committed 
>> to developing practices and products that help protect the environment
>>

-- 
Best regards, Poonam

Oracle <http://www.oracle.com>
Poonam Bajaj | Principal Member of Technical Staff
Phone: +91 80 66937451 <tel:+91%2080%2066937451> | Mobile: +91 
9844511366 <tel:+91%209844511366>
Oracle JVM Sustaining Engineering

ORACLE India Bangalore
Green Oracle <http://www.oracle.com/commitment> Oracle is committed to 
developing practices and products that help protect the environment

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