> On May 10, 2018, at 11:26 AM, Thomas Stüfe <thomas.stu...@gmail.com> wrote: > > On Thu, May 10, 2018 at 9:13 AM, Kirk Pepperdine > <kirk.pepperd...@gmail.com> wrote: >> The stacking at the safe point would be a huge win. Right now thread dump >> consistency can really confuse people as the tooling will show two threads >> owning the same lock at seemingly the same time. Reality, it’s just that >> people didn’t realize you get a safe point for each thread therefor there is >> motion in the system as you’re collecting the data. > > I am a bit confused. What tooling are you talking about?
jstack. I’ve not seen it with jcmd. But I often see 2 threads holding the same lock at the “same time” which is of course non-sense. I can dig one up for you if you’re still confused. > >> >> As an aside, it’s amazing how many dev’s aren’t aware of jcmd. Just >> yesterday after my session at Devoxx I had someone ask me about using jfr >> from the command line, many in that session had not seen jcmd before. The >> feedback was, wow, this is very useful and I wished I had of known about it >> earlier. > > Yes, jcmd is quite useful. I also really like the simple design, which > is by default up- and downward compatible (so you can talk to any VM, > new, old, it should not matter). That is just good design. We - Sap - > work to extend jcmd, to help our support folks. E.g. the whole new > VM.metaspace command chain. And simple it is….well done!!! — Kirk
