Hi all, would such a patch be acceptable:
http://cr.openjdk.java.net/~stuefe/webrevs/8213834-jvmti-reourceexhausted-shall-not-be-posted-from-compiler-thread/webrev.01/webrev/ ? As has been proposed, I am now using thread->is_hidden_from_external_view() to suppress the event. Side note, this function apparently should only ever be called from JavaThreads? To my knowledge we do not guard metaspace against allocation from non-java-threads, should we then do that? I attempted to create a jtreg test for this but this turns out to be difficult: Attempting to trigger a metaspace OOM from a compiler thread proved futile - chances for that to happen are just too low compared to other metaspace users. Only way to do this reliably would be to artificially allocate a lot of metaspace from the compiler thread - triggered by a test switch or similar? That would be very ugly though. And then, I would need to add a jvmti agent to jtreg, or adapt jtreg/vmTestbase/nsk/jvmti? Thanks, Thomas On Thu, Nov 22, 2018 at 4:22 PM Daniel D. Daugherty <daniel.daughe...@oracle.com> wrote: > > On 11/22/18 2:42 AM, David Holmes wrote: > > > > > > On 22/11/2018 5:36 pm, Thomas Stüfe wrote: > >> Hi JC, > >> > >> On Wed, Nov 21, 2018 at 6:03 PM JC Beyler <jcbey...@google.com> wrote: > >>> > >>> Hi Thomas, > >>> > >> <snip> > >>> > >>> I actually agree with not using the service thread to be honest, > >>> resource exhaustion seems to be something you'd want to know sooner > >>> than later. > >>> > >>> How about we do both? > >>> - Fix it now so that the compiler thread does not post the event > >>> because we'd rather not have crashes and that can get backported > >>> - Put out a RFE that would add the information to ThreadInfo and > >>> work through the process of a CSR/etc. to get it working for future > >>> versions? > >>> > >>> Thanks, > >>> Jc > >>> > >> > >> Makes sense, sure. But both Dan and Serguei voiced opposition to this > >> patch. Dan, Serguei, what do you think? > > > > I note neither Dan nor Serguei responded to my response to them :) > > I didn't think a response from me was needed. The last thing I said was: > > > I would have no problem suppressing the event from a "hidden" thread > > because those threads intentionally try to hide from JVM/TI. That would > > cover the case for the C1 and C2 CompilerThreads, but I don't know > > about these newer JVM/CI Compiler threads that actually run Java code... > > I read your combined response to this as not in conflict with what I said. > > The last line of your response: > > > So my preferred point solution is still to skip posting ResourceExhausted > > if the thread can not run Java code. > > matches what I said since the C1 and C2 compiler threads are hidden and > cannot run Java code. We're in agreement. > > Dan > > > > > > > Cheers, > > David > > ----- > > > >> > >> If we do not find an agreement, I would rather close this bug as WNF > >> than push it in without consensus. I would then just fix it downstream > >> in our port. > >> > >> Your proposed RFE would still make sense, but not in jdk12 anymore, > >> let alone in older releases. > >> > >> Thanks, Thomas > >> > > >
