RFR: 8242240: JfrStacktrace_lock rank not special enough

[Per Liden]

On 6/8/20 9:20 AM, Erik Österlund wrote:
> Hi,
> 
> After a ZGC event was added, we sometimes acquire the JfrStacktrace_lock 
> (special rank) when the CodeCache_lock (special rank)
> is held. This leads to an assertion error. My proposed solution is to 
> make the JfrStacktrace_lock even more special (special - 1).
> Special locks are the new normal.
> 
> Bug:
> https://bugs.openjdk.java.net/browse/JDK-8242240
> 
> Webrev:
> http://cr.openjdk.java.net/~eosterlund/8242240/webrev.00/

Looks good!

/Per

> 
> Thanks,
> /Erik