Rickard, Thank you very much for doing this!
Regards, Yunda > -----Original Message----- > From: Rickard Bäckman [mailto:rickard.back...@oracle.com] > Sent: Tuesday, May 14, 2013 1:35 PM > To: 云达(Yunda) > Cc: David Holmes; serviceability-dev@openjdk.java.net; > hotspot-runtime-...@openjdk.java.net > Subject: Re: [PATCH] EnableTracing: output from multiple threads may be mixed > together > > Yunda, > > sorry for taking a while. I created JDK-8014478 for this and I'll sponsor the > change. > > /R > > On May 10, 2013, at 4:32 AM, 云达(Yunda) wrote: > > > Thanks for looking at this, Rickard. David, do you like this option > > which is easier to read, too :) > > > > > > Regards, > > Yunda > > > >> -----Original Message----- > >> From: Rickard Bäckman [mailto:rickard.back...@oracle.com] > >> Sent: Thursday, May 09, 2013 4:53 PM > >> To: 云达(Yunda) > >> Cc: David Holmes; serviceability-dev@openjdk.java.net; > >> hotspot-runtime-...@openjdk.java.net > >> Subject: Re: [PATCH] EnableTracing: output from multiple threads may > >> be mixed together > >> > >> Looks good to me! > >> > >> /R > >> > >> On May 9, 2013, at 8:38 AM, 云达(Yunda) wrote: > >> > >>> Rickard, > >>> > >>> Actually I've considered the option and I just thought it's less > >>> elegant. But just > >> as you said, it's clearer and easier to read. The updated and tested > >> change: > >>> > >>> diff -r 627cf9e9ea31 src/share/vm/runtime/globals.hpp > >>> --- a/src/share/vm/runtime/globals.hpp Mon May 06 10:29:49 2013 > >>> -0700 > >>> +++ b/src/share/vm/runtime/globals.hpp Thu May 09 14:36:35 2013 > >>> +++ +0800 > >>> @@ -3634,7 +3634,10 @@ > >>> "Include GC cause in GC logging") > >> \ > >>> > >> \ > >>> product(bool, EnableTracing, false, > >> \ > >>> - "Enable event-based tracing") > >>> + "Enable event-based tracing") > >> \ > >>> + > >> \ > >>> + product(bool, UseLockedTracing, false, > >> \ > >>> + "Use locked-tracing when doing event-based > >>> + tracing") > >>> > >>> /* > >>> * Macros for factoring of globals > >>> diff -r 627cf9e9ea31 src/share/vm/trace/traceEventClasses.xsl > >>> --- a/src/share/vm/trace/traceEventClasses.xsl Mon May 06 10:29:49 > >>> 2013 -0700 > >>> +++ b/src/share/vm/trace/traceEventClasses.xsl Thu May 09 14:36:35 > >>> +++ 2013 +0800 > >>> @@ -132,6 +132,15 @@ > >>> void writeEvent(void) { > >>> ResourceMark rm; > >>> HandleMark hm; > >>> + if (UseLockedTracing) { > >>> + ttyLocker lock; > >>> + writeEventContent(); > >>> + } else { > >>> + writeEventContent(); > >>> + } > >>> + } > >>> + > >>> + void writeEventContent() { > >>> TraceStream ts(*tty); > >>> ts.print("<xsl:value-of select="@label"/>: ["); > >>> <xsl:apply-templates select="value|structvalue" mode="write-data"/> > >>> > >>> > >>> Regards, > >>> Yunda > >>> > >>>> -----Original Message----- > >>>> From: Rickard Bäckman [mailto:rickard.back...@oracle.com] > >>>> Sent: Wednesday, May 08, 2013 3:03 PM > >>>> To: David Holmes > >>>> Cc: 云达(Yunda); serviceability-dev@openjdk.java.net; > >>>> hotspot-runtime-...@openjdk.java.net > >>>> Subject: Re: [PATCH] EnableTracing: output from multiple threads > >>>> may be mixed together > >>>> > >>>> One option could be to move the content of writeEvent() to its own > >>>> method (maybe writeEventContent()) and just do > >>>> > >>>> if (UseLockedTracing) { > >>>> ttyLocker lock; > >>>> writeEventContent(); > >>>> } else { > >>>> writeEventContent(); > >>>> } > >>>> > >>>> I think it makes it easier to read. > >>>> > >>>> /R > >>>> > >>>> On May 8, 2013, at 2:41 AM, David Holmes wrote: > >>>> > >>>>> On 7/05/2013 10:33 PM, 云达(Yunda) wrote: > >>>>>> David, > >>>>>> > >>>>>> Sorry about the stupid mistake. And please see the tested change > below. > >>>> Since I don't find an elegant way to define a ttyLocker object, I > >>>> use the static methods of ttyLocker instead. > >>>>> > >>>>> Yeah there's no elegant solution when you need to conditionalize > >>>>> things. :( > >>>>> > >>>>> This looks fine to me but the serviceability folk should chime back in. > >>>>> > >>>>> Thanks, > >>>>> David > >>>>> > >>>>>> diff -r 627cf9e9ea31 src/share/vm/runtime/globals.hpp > >>>>>> --- a/src/share/vm/runtime/globals.hpp Mon May 06 10:29:49 2013 > >>>>>> -0700 > >>>>>> +++ b/src/share/vm/runtime/globals.hpp Tue May 07 20:04:24 2013 > >>>>>> +++ +0800 > >>>>>> @@ -3634,7 +3634,10 @@ > >>>>>> "Include GC cause in GC logging") > >>>> \ > >>>>>> > >>>> \ > >>>>>> product(bool, EnableTracing, false, > >>>> \ > >>>>>> - "Enable event-based tracing") > >>>>>> + "Enable event-based tracing") > >>>> \ > >>>>>> + > >>>> \ > >>>>>> + product(bool, UseLockedTracing, false, > >>>> \ > >>>>>> + "Use locked-tracing when doing event-based > >>>>>> + tracing") > >>>>>> > >>>>>> /* > >>>>>> * Macros for factoring of globals diff -r 627cf9e9ea31 > >>>>>> src/share/vm/trace/traceEventClasses.xsl > >>>>>> --- a/src/share/vm/trace/traceEventClasses.xsl Mon May 06 > >>>>>> 10:29:49 > >>>>>> 2013 -0700 > >>>>>> +++ b/src/share/vm/trace/traceEventClasses.xsl Tue May 07 > >>>>>> +++ 20:04:24 > >>>>>> +++ 2013 +0800 > >>>>>> @@ -132,10 +132,17 @@ > >>>>>> void writeEvent(void) { > >>>>>> ResourceMark rm; > >>>>>> HandleMark hm; > >>>>>> + int holder; > >>>>>> + if (UseLockedTracing) { > >>>>>> + holder = ttyLocker::hold_tty(); > >>>>>> + } > >>>>>> TraceStream ts(*tty); > >>>>>> ts.print("<xsl:value-of select="@label"/>: ["); > >>>>>> <xsl:apply-templates select="value|structvalue" mode="write-data"/> > >>>>>> ts.print("]\n"); > >>>>>> + if (UseLockedTracing) { > >>>>>> + ttyLocker::release_tty(holder); > >>>>>> + } > >>>>>> } > >>>>>> }; > >>>>>> > >>>>>> > >>>>>> Regards, > >>>>>> Yunda > >>>>>> > >>>>>> > >>>>>>> -----Original Message----- > >>>>>>> From: David Holmes [mailto:david.hol...@oracle.com] > >>>>>>> Sent: Tuesday, May 07, 2013 5:50 PM > >>>>>>> To: 云达(Yunda) > >>>>>>> Cc: hotspot-runtime-...@openjdk.java.net; > >>>>>>> serviceability-dev@openjdk.java.net > >>>>>>> Subject: Re: [PATCH] EnableTracing: output from multiple threads > >>>>>>> may be mixed together > >>>>>>> > >>>>>>> On 7/05/2013 7:43 PM, 云达(Yunda) wrote: > >>>>>>>> Hi David, > >>>>>>>> > >>>>>>>> Thanks for the review and I see your concern. Please see the > >>>>>>>> updated change > >>>>>>> below: > >>>>>>>> > >>>>>>>> diff -r 627cf9e9ea31 src/share/vm/runtime/globals.hpp > >>>>>>>> --- a/src/share/vm/runtime/globals.hpp Mon May 06 10:29:49 > >>>>>>>> 2013 > >>>>>>>> -0700 > >>>>>>>> +++ b/src/share/vm/runtime/globals.hpp Tue May 07 17:38:58 > >>>>>>>> +++ 2013 > >>>>>>>> +++ +0800 > >>>>>>>> @@ -3634,7 +3634,10 @@ > >>>>>>>> "Include GC cause in GC logging") > >>>>>>> \ > >>>>>>>> > >>>>>>> \ > >>>>>>>> product(bool, EnableTracing, false, > >>>>>>> \ > >>>>>>>> - "Enable event-based tracing") > >>>>>>>> + "Enable event-based tracing") > >>>>>>> \ > >>>>>>>> + > >>>>>>> \ > >>>>>>>> + product(bool, UseLockedTracing, false, > >>>>>>> \ > >>>>>>>> + "Use locked-tracing when doing event-based > >>>>>>>> + tracing") > >>>>>>>> > >>>>>>>> /* > >>>>>>>> * Macros for factoring of globals diff -r 627cf9e9ea31 > >>>>>>>> src/share/vm/trace/traceEventClasses.xsl > >>>>>>>> --- a/src/share/vm/trace/traceEventClasses.xsl Mon May 06 > >>>>>>>> 10:29:49 > >>>>>>>> 2013 -0700 > >>>>>>>> +++ b/src/share/vm/trace/traceEventClasses.xsl Tue May 07 > >>>>>>>> +++ 17:38:58 > >>>>>>>> +++ 2013 +0800 > >>>>>>>> @@ -132,6 +132,9 @@ > >>>>>>>> void writeEvent(void) { > >>>>>>>> ResourceMark rm; > >>>>>>>> HandleMark hm; > >>>>>>>> + if (UseLockedTracing) { > >>>>>>>> + ttyLocker ttyl; > >>>>>>>> + } > >>>>>>> > >>>>>>> Ah that doesn't work - the ttyLocker is block-scoped by the if > >>>>>>> statement so it will be created, grab the lock, then immediately > >>>>>>> be destructed and the lock released. > >>>>>>> > >>>>>>> David > >>>>>>> ----- > >>>>>>> > >>>>>>>> TraceStream ts(*tty); > >>>>>>>> ts.print("<xsl:value-of select="@label"/>: ["); > >>>>>>>> <xsl:apply-templates select="value|structvalue" > >>>>>>>> mode="write-data"/> > >>>>>>>> > >>>>>>>> Regards, > >>>>>>>> Yunda > >>>>>>>> > >>>>>>>>> -----Original Message----- > >>>>>>>>> From: David Holmes [mailto:david.hol...@oracle.com] > >>>>>>>>> Sent: Tuesday, May 07, 2013 10:39 AM > >>>>>>>>> To: 云达(Yunda) > >>>>>>>>> Cc: hotspot-runtime-...@openjdk.java.net; > >>>>>>>>> serviceability-dev@openjdk.java.net > >>>>>>>>> Subject: Re: [PATCH] EnableTracing: output from multiple > >>>>>>>>> threads may be mixed together > >>>>>>>>> > >>>>>>>>> Hi Yunda, > >>>>>>>>> > >>>>>>>>> There is a potential problem with using a ttyLocker here, > >>>>>>>>> depending on exactly what events are being traced and from > >>>>>>>>> where > >>>>>>>>> - you must always be in code where it is both safe to acquire > >>>>>>>>> the lock, and safe to block waiting for the lock if it is not > >>>>>>>>> available. > >>>>>>>>> > >>>>>>>>> I think I would prefer to see unlocked tracing by default with > >>>>>>>>> a flag to use locked-tracing if requested. > >>>>>>>>> > >>>>>>>>> David > >>>>>>>>> > >>>>>>>>> On 19/04/2013 6:26 PM, 云达(Yunda) wrote: > >>>>>>>>>> Hi all, > >>>>>>>>>> > >>>>>>>>>> I found that the output from multiple threads may be mixed > >>>>>>>>>> together when using EnableTracing. It happens many times in > >>>>>>>>>> my test > >>>> case like this: > >>>>>>>>>> > >>>>>>>>>> Allocation outside TLAB: [Allocation in new TLAB: [Allocation > >>>>>>>>>> in new > >>>>>>>>>> TLAB: [Allocation in new TLAB: [Class = [C, Allocation in new TLAB: > >>>>>>>>>> [Class = [I, Allocation in new TLAB: [Java Monitor Wait: > >>>>>>>>>> [Class = java/lang/String, Allocation Size = 24, Allocation > >>>>>>>>>> Size = 24, Class = java/lang/String, Class = [I, Allocation in new > TLAB: > >>>>>>>>>> [Class = [C, Allocation in new TLAB: [Allocation Size = 192] > >>>>>>>>>> > >>>>>>>>>> Class = > >>>>>>>>>> > com/sun/org/apache/xerces/internal/dom/DeferredElementNSImpl, > >>>>>>>>>> Allocation Size = 24, Allocation Size = 24, TLAB Size = > >>>>>>>>>> 23712280] > >>>>>>>>>> > >>>>>>>>>> TLAB Size = 24607080] > >>>>>>>>>> > >>>>>>>>>> Allocation Size = 24, Monitor Class = > >>>>>>>>>> java/lang/ref/Reference$Lock, TLAB Size = 25054480] > >>>>>>>>>> > >>>>>>>>>> TLAB Size = 25054480] > >>>>>>>>>> > >>>>>>>>>> Allocation in new TLAB: [Class = [CTLAB Size = 24607080] > >>>>>>>>>> > >>>>>>>>>> Allocation Size = 72, Class = [C, TLAB Size = 24159728] > >>>>>>>>>> > >>>>>>>>>> , Allocation Size = 32, TLAB Size = 23712288] > >>>>>>>>>> > >>>>>>>>>> It's very confusing and it's even not easy to tell how many > >>>>>>>>>> events there are. I think the reason is that the writeEvent() > >>>>>>>>>> method of each > >>>>>>>>>> Event* class output the fields of event one by one without > >>>>>>>>>> using any lock. So I made a small patch which add ttyLocker > >>>>>>>>>> to > >>>>>>>>>> writeEvent() method and after applying this patch there's no > >>>>>>>>>> output mixed together in my test case(against > >>>>>>> http://hg.openjdk.java.net/hsx/hsx24/hotspot/): > >>>>>>>>>> > >>>>>>>>>> diff -r edd1619a3ae4 src/share/vm/trace/traceEventClasses.xsl > >>>>>>>>>> > >>>>>>>>>> --- a/src/share/vm/trace/traceEventClasses.xsl Thu Apr 18 > >>>> 13:50:58 > >>>>>>>>>> 2013 -0700 > >>>>>>>>>> > >>>>>>>>>> +++ b/src/share/vm/trace/traceEventClasses.xsl Fri Apr 19 > >>>>>>>>>> +++ 16:12:38 > >>>>>>>>>> +++ 2013 > >>>>>>>>>> +0800 > >>>>>>>>>> > >>>>>>>>>> @@ -132,6 +132,7 @@ > >>>>>>>>>> > >>>>>>>>>> void writeEvent(void) { > >>>>>>>>>> > >>>>>>>>>> ResourceMark rm; > >>>>>>>>>> > >>>>>>>>>> HandleMark hm; > >>>>>>>>>> > >>>>>>>>>> + ttyLocker ttyl; > >>>>>>>>>> > >>>>>>>>>> TraceStream ts(*tty); > >>>>>>>>>> > >>>>>>>>>> ts.print("<xsl:value-of select="@label"/>: ["); > >>>>>>>>>> > >>>>>>>>>> <xsl:apply-templates select="value|structvalue" > >>>>>>>>>> mode="write-data"/> > >>>>>>>>>> > >>>>>>>>>> I searched before sending this mail I didn't find anyone who > >>>>>>>>>> covering thisJ > >>>>>>>>>> > >>>>>>>>>> Regards, > >>>>>>>>>> > >>>>>>>>>> Yunda > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> ------------------------------------------------------------- > >>>>>>>>>> -- > >>>>>>>>>> -- > >>>>>>>>>> --- > >>>>>>>>>> -- > >>>>>>>>>> -- > >>>>>>>>>> > >>>>>>>>>> This email (including any attachments) is confidential and > >>>>>>>>>> may be legally privileged. 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