RFR (S): 7176220 'Full GC' events miss date stamp information occasionally

[Jon Masamitsu]

Andreas,

Please send a short sample of a new log.  I want to see if
our log parsers work on the new log.  If you have not already
done so, please do not push this until I've checked that the
logs still parse.

Jon

On 5/14/2013 2:21 AM, Andreas Eriksson wrote:
> Hi,
>
> I changed the date and time stamping calls to use the guarded 
> convenience variants.
> Both of these calls suffixes a ": " automatically. See 
> share/vm/utilities/ostream.hpp line 99 and 105.
>
> It currently looks like this:
> % ./hsx24_hotspot-build/bin/java -Xmx2m -verbose:gc 
> -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps HumongousAlloc
> 2013-05-14T11:17:28.340+0200: 0.050: [GC 1896K->421K(3136K), 0.0011640 
> secs]
> 2013-05-14T11:17:28.341+0200: 0.051: [GC 2329K->437K(3136K), 0.0029750 
> secs]
>
> This is how it looked before as well:
> % ~/builds/linux-amd64/7u25/bin/java -Xmx2m -verbose:gc 
> -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps HumongousAlloc
> 2013-05-14T11:17:31.603+0200: 0.059: [GC 2025K->417K(3136K), 0.0008100 
> secs]
> 2013-05-14T11:17:31.605+0200: 0.060: [GC 2325K->417K(3136K), 0.0015140 
> secs]
>
> Thanks for looking at this.
>
> /Andreas
>
> On 2013-05-14 08:23, Bengt Rutisson wrote:
>>
>> Hi Andreas,
>>
>> Looks good.
>>
>> One question regarding the change in GCTraceTime:
>>
>> http://cr.openjdk.java.net/~aeriksso/7176220/webrev.00/src/share/vm/gc_implementation/shared/gcTraceTime.cpp.udiff.html 
>>
>>
>> It looks to me like we are missing a ": " in the new version. Maybe 
>> it is ok to loose this character in the log format, but a safer 
>> change may be:
>>
>> if (PrintGCTimeStamps || PrintGCDateStamps) {
>>   gclog_or_tty->date_stamp(PrintGCDateStamps);
>>   gclog_or_tty->stamp(PrintGCTimeStamps);
>> gclog_or_tty->print(": ");
>> }
>>
>> This actually still changes the ": " behavior since since you didn't 
>> use to get a ": " if you only had PrintGCDateStamps enabled. But I 
>> think this is a more expected behavior.
>>
>> Thanks,
>> Bengt
>>
>> On 5/13/13 6:01 PM, Andreas Eriksson wrote:
>>> Hi all,
>>>
>>> Please take a look at my changes for bug 7176220.
>>> The problem is that CMS sometimes misses datestamps for time trace 
>>> printouts.
>>>
>>> The proposed fix is to move the datestamp print logic into the class 
>>> that handles time trace printouts, GCTraceTime.
>>> This would make it consistent with timestamps, which are already 
>>> printed from there.
>>>
>>> Bugs.sun:
>>> http://bugs.sun.com/view_bug.do?bug_id=7176220
>>>
>>> JIRA:
>>> https://jbs.oracle.com/bugs/browse/JDK-7176220
>>>
>>> Webrev:
>>> http://cr.openjdk.java.net/~aeriksso/7176220/webrev.00/
>>>
>>> Testing:
>>> jprt, jtreg
>>>
>>> Thanks,
>>> Andreas
>>>
>>
>
>