Pinging the serviceability tracing experts please! David
On 24/12/2015 12:25 AM, Yasumasa Suenaga wrote: > Hi David, > >>> 1. Initialize JavaThread before calling apply_ergo() in create_vm(). >> >> That is not likely to be an option - it would likely be far too >> disruptive to the initialization sequence. > > Agree. Thus I choose 2. > >> We will have to wait for the tracing experts to have a good look at >> this. > > I'm waiting that the tracing experts join this discussion. > > > Thanks, > > Yasumasa > > > On 2015/12/23 13:20, David Holmes wrote: >> Hi Yasumasa, >> >> On 23/12/2015 11:49 AM, Yasumasa Suenaga wrote: >>> Hi David, >>> >>> I've added callstack when JVM crashed: >>> >>> https://bugs.openjdk.java.net/browse/JDK-8145788?focusedCommentId=13880225&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13880225 >> >> Thanks for that. >> >>> This crash occurrs in Arguments::apply_ergo() in Threads::create_vm(). >>> apply_ergo() calls before JavaThread initialization. >>> >>> I think that TraceEvent can avoid crash with two approach: >>> >>> 1. Initialize JavaThread before calling apply_ergo() in create_vm(). >> >> That is not likely to be an option - it would likely be far too >> disruptive to the initialization sequence. >> >>> 2. Avoid crash at TraceEvent when it is called before JavaThread >>> initialization. >> >> Or don't call it at all. >> >> We will have to wait for the tracing experts to have a good look at >> this. We end up in code that is not expecting to be run before more of >> the VM is initialized, so we have to look at what else may be being >> assumed and then decide whether to handle the situation or avoid it. >> >> Thanks, >> David >> >>> >>> Thanks, >>> >>> Yasumasa >>> >>> >>> On 2015/12/22 21:19, David Holmes wrote: >>>> On 19/12/2015 1:50 AM, Yasumasa Suenaga wrote: >>>>> Hi all, >>>>> >>>>> I encountered JVM crash when I passed -XX:+EnableTracing. >>>>> >>>>> I checked core image, it crashed in >>>>> EventBooleanFlagChanged::writeEvent() >>>>> which is called by Arguments::apply_ergo() because thread had not >>>>> been >>>>> initialized. (JVM seems to log changing GC algorithm to G1.) >>>> >>>> This seems like a logic error to me - something is trying to happen too >>>> early during VM initialization. We need to look at exactly what we are >>>> trying to do here, not just work around the crash. >>>> >>>> David >>>> ----- >>>> >>>>> writeEvent() uses ResourceMark. Default constructor of ResourceMark >>>>> uses >>>>> ResourceArea in current thread. So ResourceMark in writeEvent() >>>>> should >>>>> pass valid ResourceArea. >>>>> >>>>> I think this issue is in traceEventClasses.xsl . >>>>> However, my environment (GCC 5.3.1 on Fedora23) cannot build it because >>>>> -Werror=maybe-uninitialized was occurred. >>>>> So I also fixed them together. >>>>> >>>>> I've uploaded webrev. Could you review it? >>>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8145788/webrev.00/ >>>>> >>>>> I'm jdk9 committer, however I cannot access JPRT. >>>>> So I need a sponsor. >>>>> >>>>> >>>>> Thanks, >>>>> >>>>> Yasumasa >>>>>
