Increased safepoint cleanup tasks in Java 11 (vs 8)

[Vitaly Davidovich]

On Wed, Jun 5, 2019 at 8:47 AM Thomas Schatzl <thomas.schatzl at oracle.com>
wrote:

> Hi,
>
> On Wed, 2019-06-05 at 08:33 -0400, Vitaly Davidovich wrote:
> > Hi all,
> >
> [...]
> >
> > My guess would be it's SAFEPOINT_CLEANUP_STRING_TABLE_REHASH because
> > tiered compilation is disabled, ParallelGC is being used, and biased
> > locking is disabled; all of this is the same as on Java 8.  Or might
> > this be something else? Presumably it's something "new" in Java 11
> > that triggers inside
> >
>
> https://github.com/openjdk/jdk11u/blob/737d8437886ad97c6ed21a25b9911c10b3886f61/src/hotspot/share/runtime/safepoint.cpp#L644
> >
> > Does anyone have ideas on pinpointing this further? How do I get the
> > precise cleanup operation to show up in the log?
>
> Given above link, considering the "TraceTime timer(name,
> TRACETIME_LOG(Info, safepoint, cleanup))" lines, I would try adding
> safepoint+cleanup=info to your log options.
>
Ah, thanks Thomas! I "saw" the "cleanup" in there too, but didn't connect
the dots that I had to also include that as a ULF tag (since already had
"safepoint").  Makes sense.  I will try.

>
> Hth,
>   Thomas
>
>
>