Questions regarding GC

[Tao Mao]

Hi Jun,

1. Search for PLAB

2. The following are pretty much all printing-GC-related flags we have:
PrintGC
PrintGCDetails
PrintGCTimeStamps
PrintGCDateStamps
PrintTenuringDistribution
PrintGCTaskTimeStamps
PrintApplicationConcurrentTime
PrintApplicationStoppedTime

You might want to try the last three options. Plus, "-XX:+UseG1GC
+XX:+PrintGCDetails" has more verbose gc logs than other collectors'.


Thanks.
Tao Mao


On Fri, Feb 19, 2016 at 8:15 PM, Jun Zhuang <jun.zhuang at hobsons.com> wrote:

> Hi,
>
>
>
> I tried to find answers to a couple of questions I have regarding GC but
> found nothing on the Internet, I wonder if the experts here can help me out?
>
>
>
> ·         How are objects stored in the old generation when promoted from
> the young gen or survivor space? Does the JVM use something similar to the
> TLAB?
>
> ·         The time for a young GC pause consists stack scan, card scan
> and copying, are there command line options for me to get a time breakdown
> for those times in the GC log?
>
>
>
> Thanks,
>
> Jun
>
>
>
> *Jun Zhuang*
>
> *Sr. Performance QA Engineer* | Hobsons
> <https://www.hobsons.com/?utm_source=outlook&utm_medium=email&utm_campaign=banner_02.12.16_general>
>
> T: +1 513 746 2288 | jun.zhuang at hobsons.com
>
> 50 E-Business Way, Suite 300 | Cincinnati, OH 45241 | USA
>
>
>
>
>
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