RFR(L) 8153224 Monitor deflation prolong safepoints (CR14/v2.14/17-for-jdk15)

Daniel D. Daugherty daniel.daugherty at oracle.com
Tue Jun 2 00:30:15 UTC 2020


Hi David,

On 6/1/20 7:58 PM, David Holmes wrote:
> Hi Dan,
>
> Sorry for the delay.

No worries. It's always worth waiting for your code review in general
and, with the complexity of this project, it's on my must-do list!


>
> On 28/05/2020 3:20 am, Daniel D. Daugherty wrote:
>> Greetings,
>>
>> Erik O. had an idea for changing the three part async deflation protocol
>> into a two part async deflation protocol where the second part (setting
>> the contentions field to -max_jint) is a linearization point. I've taken
>> Erik's proposal (which was relative to CR12/v2.12/15-for-jdk15), merged
>> it with CR13/v2.13/16-for-jdk15, and made a few minor tweaks.
>>
>> I have attached the change list from CR13 to CR14 and I've also added a
>> link to the CR13-to-CR14-changes file to the webrevs so it should be 
>> easy
>> to find.
>>
>> Main bug URL:
>>
>>      JDK-8153224 Monitor deflation prolong safepoints
>>      https://bugs.openjdk.java.net/browse/JDK-8153224
>>
>> The project is currently baselined on jdk-15+24.
>>
>> Here's the full webrev URL for those folks that want to see all of the
>> current Async Monitor Deflation code in one go (v2.14 full):
>>
>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/17-for-jdk15+24.v2.14.full/ 
>>
>>
>> Some folks might want to see just what has changed since the last review
>> cycle so here's a webrev for that (v2.14 inc):
>>
>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/17-for-jdk15+24.v2.14.inc/ 
>
>
> src/hotspot/share/runtime/synchronizer.cpp
>
> I'm having a little trouble keeping the _contentions relationships in 
> my head. In particular with this change I can't quite grok the:
>
> // Deferred decrement for the JT EnterI() that cancelled the async 
> deflation.
> mid->add_to_contentions(-1);
>
> change. I kind of get EnterI() does an extra increment and the 
> deflator thread does the above matching decrement. But given the two 
> changes can happen in any order I'm not sure what the possible visible 
> values for _contentions will be and how that might affect other code 
> inspecting it?

I have a sub-section in the OpenJDK wiki dedicated to this particular race:

https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation#AsyncMonitorDeflation-T-enterWinsByCancellationViaDEFLATER_MARKERSwap

In order for this race condition to manifest, the T-enter thread has to
successfully swap the owner field's DEFLATER_MARKER value for Self. That
swap will eventually cause the T-deflate thread to realize that the async
deflation that it started has been canceled.

The diagram shows the progression of contentions values:

- ObjectMonitor box 1 shows contentions == 1 because T-enter incremented
   the contentions field

- ObjectMonitor box 2 shows contentions == 2 because EnterI() did the
   extra increment.

- ObjectMonitor box 3 shows contentions == 1 because T-enter did the
   regular contentions decrement.

- ObjectMonitor box 4 shows contentions == 0 because T-deflate did the
   extra contentions decrement.

Now it is possible for T-deflate to do the extra decrement before T-enter
does the extra increment. If I were to add another diagram to show that
variant of the race, that progression of contentions values would be:

- ObjectMonitor box 1 shows contentions == 1 because T-enter incremented
   the contentions field

- ObjectMonitor box 2 shows contentions == 0 because T-deflate did the
   extra contentions decrement.

- ObjectMonitor box 3 shows contentions == 1 because EnterI() did the
   extra increment.

- ObjectMonitor box 4 shows contentions == 0 because T-enter did the
   regular contentions decrement.

Notice that in this second scenario the contentions field never goes
negative so there's nothing to confuse a potential caller of
is_being_async_deflated():

inline bool ObjectMonitor::is_being_async_deflated() {
   return AsyncDeflateIdleMonitors && contentions() < 0;
}

It is not possible for T-deflate's extra decrement of the contentions
field to make the contentions field negative. That decrement only happens
when T-deflate detects that the async deflation has been canceled and
async deflation can only be canceled after T-enter has already made the
contentions field > 0.

Please let me know if this resolves your concern about:

> // Deferred decrement for the JT EnterI() that cancelled the async 
> deflation.
> mid->add_to_contentions(-1); 

I'm not planning to update the OpenJDK wiki to add a second variant of
the cancellation race. Please let me know if that is okay.

>
> But otherwise the changes in this version seem good and overall the 
> protocol seems simpler.

This sounds like a thumbs up, but I'm looking for something more definitive.


> I'm still going to spend some more time going over the complete webrev 
> to get a fuller sense of things.

As always, if you find something after I've pushed, we'll deal with it.

Thanks for your many re-reviews for this project!!

Dan


>
> Thanks,
> David
>
>>
>>
>> The OpenJDK wiki has been updated for v2.14.
>>
>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation
>>
>> The jdk-15+24 based v2.14 version of the patch has gone thru Mach5 
>> Tier[1-5]
>> testing with no related failures; Mach5 Tier[67] are running now and 
>> so far
>> have no related failures. I'll kick off Mach5 Tier8 after the other 
>> tiers
>> have finished since Mach5 is a bit busy right now.
>>
>> I'm also running my usual inflation stress testing on Linux-X64 and 
>> macOSX
>> and so far there are no issues.
>>
>> Thanks, in advance, for any questions, comments or suggestions.
>>
>> Dan
>>
>>
>> On 5/21/20 2:53 PM, Daniel D. Daugherty wrote:
>>> Greetings,
>>>
>>> I have made changes to the Async Monitor Deflation code in response to
>>> the CR12/v2.12/15-for-jdk15 code review cycle. Thanks to David H. and
>>> Erik O. for their OpenJDK reviews in the v2.12 round!
>>>
>>> I have attached the change list from CR12 to CR13 and I've also added a
>>> link to the CR12-to-CR13-changes file to the webrevs so it should be 
>>> easy
>>> to find.
>>>
>>> Main bug URL:
>>>
>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>     https://bugs.openjdk.java.net/browse/JDK-8153224
>>>
>>> The project is currently baselined on jdk-15+24.
>>>
>>> Here's the full webrev URL for those folks that want to see all of the
>>> current Async Monitor Deflation code in one go (v2.13 full):
>>>
>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/16-for-jdk15%2b24.v2.13.full/ 
>>>
>>>
>>> Some folks might want to see just what has changed since the last 
>>> review
>>> cycle so here's a webrev for that (v2.13 inc):
>>>
>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/16-for-jdk15%2b24.v2.13.inc/ 
>>>
>>>
>>>
>>> The OpenJDK wiki is currently at v2.13 and might require minor 
>>> tweaks for v2.12
>>> and v2.13. Yes, I need to make yet another crawl thru review of it...
>>>
>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation
>>>
>>> The jdk-15+24 based v2.13 version of the patch is going thru the usual
>>> Mach5 testing right now. It is also going thru my usual inflation 
>>> stress
>>> testing on Linux-X64 and macOSX.
>>>
>>> Thanks, in advance, for any questions, comments or suggestions.
>>>
>>> Dan
>>>
>>> On 5/14/20 5:40 PM, Daniel D. Daugherty wrote:
>>>> Greetings,
>>>>
>>>> I have made changes to the Async Monitor Deflation code in response to
>>>> the CR11/v2.11/14-for-jdk15 code review cycle. Thanks to David H., 
>>>> Erik O.,
>>>> and Robbin for their OpenJDK reviews in the v2.11 round!
>>>>
>>>> I have attached the change list from CR11 to CR12 and I've also 
>>>> added a
>>>> link to the CR11-to-CR12-changes file to the webrevs so it should 
>>>> be easy
>>>> to find.
>>>>
>>>> Main bug URL:
>>>>
>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>     https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>
>>>> The project is currently baselined on jdk-15+23.
>>>>
>>>> Here's the full webrev URL for those folks that want to see all of the
>>>> current Async Monitor Deflation code in one go (v2.12 full):
>>>>
>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/15-for-jdk15%2b23.v2.12.full/ 
>>>>
>>>>
>>>> Some folks might want to see just what has changed since the last 
>>>> review
>>>> cycle so here's a webrev for that (v2.12 inc):
>>>>
>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/15-for-jdk15%2b23.v2.12.inc/ 
>>>>
>>>>
>>>>
>>>> The OpenJDK wiki is currently at v2.11 and might require minor 
>>>> tweaks for v2.12:
>>>>
>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation
>>>>
>>>> The jdk-15+23 based v2.12 version of the patch is going thru the usual
>>>> Mach5 testing right now.
>>>>
>>>> Thanks, in advance, for any questions, comments or suggestions.
>>>>
>>>> Dan
>>>>
>>>>
>>>> On 5/7/20 1:08 PM, Daniel D. Daugherty wrote:
>>>>> Greetings,
>>>>>
>>>>> I have made changes to the Async Monitor Deflation code in 
>>>>> response to
>>>>> the CR10/v2.10/13-for-jdk15 code review cycle and DaCapo-h2 perf 
>>>>> testing.
>>>>> Thanks to Erik O., Robbin and David H. for their OpenJDK reviews 
>>>>> in the
>>>>> v2.10 round! Thanks to Eric C. for his help in isolating the 
>>>>> DaCapo-h2
>>>>> performance regression.
>>>>>
>>>>> With the removal of ref_counting and the ObjectMonitorHandle 
>>>>> class, the
>>>>> Async Monitor Deflation project is now closer to Carsten's original
>>>>> prototype. While ref_counting gave us ObjectMonitor* safety 
>>>>> enforced by
>>>>> code, I saw a ~22.8% slow down with -XX:-AsyncDeflateIdleMonitors 
>>>>> ("off"
>>>>> mode). The slow down with "on" mode -XX:+AsyncDeflateIdleMonitors 
>>>>> is ~17%.
>>>>>
>>>>> I have attached the change list from CR10 to CR11 instead of 
>>>>> putting it in
>>>>> the body of this email. I've also added a link to the 
>>>>> CR10-to-CR11-changes
>>>>> file to the webrevs so it should be easy to find.
>>>>>
>>>>> Main bug URL:
>>>>>
>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>     https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>
>>>>> The project is currently baselined on jdk-15+21.
>>>>>
>>>>> Here's the full webrev URL for those folks that want to see all of 
>>>>> the
>>>>> current Async Monitor Deflation code in one go (v2.11 full):
>>>>>
>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/14-for-jdk15%2b21.v2.11.full/ 
>>>>>
>>>>>
>>>>> Some folks might want to see just what has changed since the last 
>>>>> review
>>>>> cycle so here's a webrev for that (v2.11 inc):
>>>>>
>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/14-for-jdk15%2b21.v2.11.inc/ 
>>>>>
>>>>>
>>>>> Because of the removal of ref_counting and the ObjectMonitorHandle 
>>>>> class, the
>>>>> incremental webrev is a bit noisier than I would have preferred.
>>>>>
>>>>>
>>>>> The OpenJDK wiki has NOT YET been updated for this round of changes:
>>>>>
>>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation
>>>>>
>>>>> The jdk-15+21 based v2.11 version of the patch has been thru Mach5 
>>>>> tier[1-6]
>>>>> testing on Oracle's usual set of platforms. Mach5 tier[78] are 
>>>>> still running.
>>>>> I'm running the v2.11 patch through my usual set of stress testing on
>>>>> Linux-X64 and macOSX.
>>>>>
>>>>> I'm planning to do a SPECjbb2015, DaCapo-h2 and volano round on the
>>>>> CR11/v2.11/14-for-jdk15 bits.
>>>>>
>>>>> Thanks, in advance, for any questions, comments or suggestions.
>>>>>
>>>>> Dan
>>>>>
>>>>>
>>>>> On 2/26/20 5:22 PM, Daniel D. Daugherty wrote:
>>>>>> Greetings,
>>>>>>
>>>>>> I have made changes to the Async Monitor Deflation code in 
>>>>>> response to
>>>>>> the CR9/v2.09/12-for-jdk14 code review cycle. Thanks to Robbin 
>>>>>> and Erik O.
>>>>>> for their comments in this round!
>>>>>>
>>>>>> With the extraction and push of {8235931,8236035,8235795} to 
>>>>>> JDK15, the
>>>>>> Async Monitor Deflation code is back to "just" async deflation 
>>>>>> changes!
>>>>>>
>>>>>> I have attached the change list from CR9 to CR10 instead of 
>>>>>> putting it in
>>>>>> the body of this email. I've also added a link to the 
>>>>>> CR9-to-CR10-changes
>>>>>> file to the webrevs so it should be easy to find.
>>>>>>
>>>>>> Main bug URL:
>>>>>>
>>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>>     https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>>
>>>>>> The project is currently baselined on jdk-15+11.
>>>>>>
>>>>>> Here's the full webrev URL for those folks that want to see all 
>>>>>> of the
>>>>>> current Async Monitor Deflation code in one go (v2.10 full):
>>>>>>
>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/13-for-jdk15+11.v2.10.full/ 
>>>>>>
>>>>>>
>>>>>> Some folks might want to see just what has changed since the last 
>>>>>> review
>>>>>> cycle so here's a webrev for that (v2.10 inc):
>>>>>>
>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/13-for-jdk15+11.v2.10.inc/ 
>>>>>>
>>>>>>
>>>>>> Since we backed out the HandshakeAfterDeflateIdleMonitors option 
>>>>>> and the
>>>>>> C2 ref_count changes and updated the copyright years, the "inc" 
>>>>>> webrev has
>>>>>> a bit more noise in it than usual. Sorry about that!
>>>>>>
>>>>>> The OpenJDK wiki has been updated for this round of changes:
>>>>>>
>>>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation 
>>>>>>
>>>>>>
>>>>>> The jdk-15+11 based v2.10 version of the patch has been thru 
>>>>>> Mach5 tier[1-7]
>>>>>> testing on Oracle's usual set of platforms. Mach5 tier8 is still 
>>>>>> running.
>>>>>> I'm running the v2.10 patch through my usual set of stress 
>>>>>> testing on
>>>>>> Linux-X64 and macOSX.
>>>>>>
>>>>>> I'm planning to do a SPECjbb2015 round on the 
>>>>>> CR10/v2.20/13-for-jdk15 bits.
>>>>>>
>>>>>> Thanks, in advance, for any questions, comments or suggestions.
>>>>>>
>>>>>> Dan
>>>>>>
>>>>>>
>>>>>> On 2/4/20 9:41 AM, Daniel D. Daugherty wrote:
>>>>>>> Greetings,
>>>>>>>
>>>>>>> This project is no longer targeted to JDK14 so this is NOT an 
>>>>>>> urgent code
>>>>>>> review request.
>>>>>>>
>>>>>>> I've extracted the following three fixes from the Async Monitor 
>>>>>>> Deflation
>>>>>>> project code:
>>>>>>>
>>>>>>>     JDK-8235931 add OM_CACHE_LINE_SIZE and use smaller size on 
>>>>>>> SPARCv9 and X64
>>>>>>>     https://bugs.openjdk.java.net/browse/JDK-8235931
>>>>>>>
>>>>>>>     JDK-8236035 refactor ObjectMonitor::set_owner() and _owner 
>>>>>>> field setting
>>>>>>>     https://bugs.openjdk.java.net/browse/JDK-8236035
>>>>>>>
>>>>>>>     JDK-8235795 replace monitor list 
>>>>>>> mux{Acquire,Release}(&gListLock) with spin locks
>>>>>>>     https://bugs.openjdk.java.net/browse/JDK-8235795
>>>>>>>
>>>>>>> Each of these has been reviewed separately and will be pushed to 
>>>>>>> JDK15
>>>>>>> in the near future (possibly by the end of this week). Of 
>>>>>>> course, there
>>>>>>> were improvements during these review cycles and the purpose of 
>>>>>>> this
>>>>>>> e-mail is to provided updated webrevs for this fix 
>>>>>>> (CR9/v2.09/12-for-jdk14)
>>>>>>> within the revised context provided by {8235931, 8236035, 8235795}.
>>>>>>>
>>>>>>> Main bug URL:
>>>>>>>
>>>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>>>     https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>>>
>>>>>>> The project is currently baselined on jdk-14+34.
>>>>>>>
>>>>>>> Here's the full webrev URL for those folks that want to see all 
>>>>>>> of the
>>>>>>> current Async Monitor Deflation code along with {8235931, 
>>>>>>> 8236035, 8235795}
>>>>>>> in one go (v2.09b full):
>>>>>>>
>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/12-for-jdk14.v2.09b.full/ 
>>>>>>>
>>>>>>>
>>>>>>> Compare the open.patch file in 12-for-jdk14.v2.09.full and 
>>>>>>> 12-for-jdk14.v2.09b.full
>>>>>>> using your favorite file comparison/merge tool to see how Async 
>>>>>>> Monitor Deflation
>>>>>>> evolved due to {8235931, 8236035, 8235795}.
>>>>>>>
>>>>>>> Some folks might want to see just the Async Monitor Deflation 
>>>>>>> code on top of
>>>>>>> {8235931, 8236035, 8235795} so here's a webrev for that (v2.09b 
>>>>>>> inc):
>>>>>>>
>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/12-for-jdk14.v2.09b.inc/ 
>>>>>>>
>>>>>>>
>>>>>>> These webrevs have gone thru several Mach5 Tier[1-8] runs along 
>>>>>>> with
>>>>>>> my usual stress testing and SPECjbb2015 testing and there aren't 
>>>>>>> any
>>>>>>> surprises relative to CR9/v2.09/12-for-jdk14.
>>>>>>>
>>>>>>> Thanks, in advance, for any questions, comments or suggestions.
>>>>>>>
>>>>>>> Dan
>>>>>>>
>>>>>>>
>>>>>>> On 12/11/19 3:41 PM, Daniel D. Daugherty wrote:
>>>>>>>> Greetings,
>>>>>>>>
>>>>>>>> I have made changes to the Async Monitor Deflation code in 
>>>>>>>> response to
>>>>>>>> the CR8/v2.08/11-for-jdk14 code review cycle. Thanks to David 
>>>>>>>> H., Robbin
>>>>>>>> and Erik O. for their comments!
>>>>>>>>
>>>>>>>> This project is no longer targeted to JDK14 so this is NOT an 
>>>>>>>> urgent code
>>>>>>>> review request. The primary purpose of this webrev is simply to 
>>>>>>>> close the
>>>>>>>> CR8/v2.08/11-for-jdk14 code review loop and to let folks see 
>>>>>>>> how I resolved
>>>>>>>> the code review comments from that round.
>>>>>>>>
>>>>>>>> Most of the comments in the CR8/v2.08/11-for-jdk14 code review 
>>>>>>>> cycle were
>>>>>>>> on the monitor list changes so I'm going to take a look at 
>>>>>>>> extracting those
>>>>>>>> changes into a standalone patch. Switching from 
>>>>>>>> Thread::muxAcquire(&gListLock)
>>>>>>>> and Thread::muxRelease(&gListLock) to finer grained internal 
>>>>>>>> spin locks needs
>>>>>>>> to be thoroughly reviewed and the best way to do that is 
>>>>>>>> separately from the
>>>>>>>> Async Monitor Deflation changes. Thanks to Coleen for 
>>>>>>>> suggesting doing this
>>>>>>>> extraction earlier.
>>>>>>>>
>>>>>>>> I have attached the change list from CR8 to CR9 instead of 
>>>>>>>> putting it in
>>>>>>>> the body of this email. I've also added a link to the 
>>>>>>>> CR8-to-CR9-changes
>>>>>>>> file to the webrevs so it should be easy to find.
>>>>>>>>
>>>>>>>> Main bug URL:
>>>>>>>>
>>>>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>>>>     https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>>>>
>>>>>>>> The project is currently baselined on jdk-14+26.
>>>>>>>>
>>>>>>>> Here's the full webrev URL for those folks that want to see all 
>>>>>>>> of the
>>>>>>>> current Async Monitor Deflation code in one go (v2.09 full):
>>>>>>>>
>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/12-for-jdk14.v2.09.full/ 
>>>>>>>>
>>>>>>>>
>>>>>>>> Some folks might want to see just what has changed since the 
>>>>>>>> last review
>>>>>>>> cycle so here's a webrev for that (v2.09 inc):
>>>>>>>>
>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/12-for-jdk14.v2.09.inc/ 
>>>>>>>>
>>>>>>>>
>>>>>>>> The OpenJDK wiki has NOT yet been updated for this round of 
>>>>>>>> changes:
>>>>>>>>
>>>>>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation 
>>>>>>>>
>>>>>>>>
>>>>>>>> The jdk-14+26 based v2.09 version of the patch has been thru 
>>>>>>>> Mach5 tier[1-7]
>>>>>>>> testing on Oracle's usual set of platforms. Mach5 tier8 is 
>>>>>>>> still running.
>>>>>>>> A slightly older version of the v2.09 patch has also been 
>>>>>>>> through my usual
>>>>>>>> set of stress testing on Linux-X64 and macOSX with the addition 
>>>>>>>> of Robbin's
>>>>>>>> "MoCrazy 1024" test running in parallel on Linux-X64 with the 
>>>>>>>> other tests in
>>>>>>>> my lab. The "MoCrazy 1024" has been going for > 5 days and 
>>>>>>>> 6700+ iterations
>>>>>>>> without any failures.
>>>>>>>>
>>>>>>>> I'm planning to do a SPECjbb2015 round on the 
>>>>>>>> CR9/v2.09/12-for-jdk14 bits.
>>>>>>>>
>>>>>>>> Thanks, in advance, for any questions, comments or suggestions.
>>>>>>>>
>>>>>>>> Dan
>>>>>>>>
>>>>>>>>
>>>>>>>> On 11/4/19 4:03 PM, Daniel D. Daugherty wrote:
>>>>>>>>> Greetings,
>>>>>>>>>
>>>>>>>>> I have made changes to the Async Monitor Deflation code in 
>>>>>>>>> response to
>>>>>>>>> the CR7/v2.07/10-for-jdk14 code review cycle. Thanks to David 
>>>>>>>>> H., Robbin
>>>>>>>>> and Erik O. for their comments!
>>>>>>>>>
>>>>>>>>> JDK14 Rampdown phase one is coming on Dec. 12, 2019 and the 
>>>>>>>>> Async Monitor
>>>>>>>>> Deflation project needs to push before Nov. 12, 2019 in order 
>>>>>>>>> to allow
>>>>>>>>> for sufficient bake time for such a big change. Nov. 12 is 
>>>>>>>>> _next_ Tuesday
>>>>>>>>> so we have 8 days from today to finish this code review cycle 
>>>>>>>>> and push
>>>>>>>>> this code for JDK14.
>>>>>>>>>
>>>>>>>>> Carsten and Roman! Time for you guys to chime in again on the 
>>>>>>>>> code reviews.
>>>>>>>>>
>>>>>>>>> I have attached the change list from CR7 to CR8 instead of 
>>>>>>>>> putting it in
>>>>>>>>> the body of this email. I've also added a link to the 
>>>>>>>>> CR7-to-CR8-changes
>>>>>>>>> file to the webrevs so it should be easy to find.
>>>>>>>>>
>>>>>>>>> Main bug URL:
>>>>>>>>>
>>>>>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>>>>>
>>>>>>>>> The project is currently baselined on jdk-14+21.
>>>>>>>>>
>>>>>>>>> Here's the full webrev URL for those folks that want to see 
>>>>>>>>> all of the
>>>>>>>>> current Async Monitor Deflation code in one go (v2.08 full):
>>>>>>>>>
>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/11-for-jdk14.v2.08.full 
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Some folks might want to see just what has changed since the 
>>>>>>>>> last review
>>>>>>>>> cycle so here's a webrev for that (v2.08 inc):
>>>>>>>>>
>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/11-for-jdk14.v2.08.inc/ 
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> The OpenJDK wiki did not need any changes for this round:
>>>>>>>>>
>>>>>>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation 
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> The jdk-14+21 based v2.08 version of the patch has been thru 
>>>>>>>>> Mach5 tier[1-8]
>>>>>>>>> testing on Oracle's usual set of platforms. It has also been 
>>>>>>>>> through my usual
>>>>>>>>> set of stress testing on Linux-X64, macOSX and Solaris-X64 
>>>>>>>>> with the addition
>>>>>>>>> of Robbin's "MoCrazy 1024" test running in parallel with the 
>>>>>>>>> other tests in
>>>>>>>>> my lab. Some testing is still running, but so far there are no 
>>>>>>>>> new regressions.
>>>>>>>>>
>>>>>>>>> I have not yet done a SPECjbb2015 round on the 
>>>>>>>>> CR8/v2.08/11-for-jdk14 bits.
>>>>>>>>>
>>>>>>>>> Thanks, in advance, for any questions, comments or suggestions.
>>>>>>>>>
>>>>>>>>> Dan
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 10/17/19 5:50 PM, Daniel D. Daugherty wrote:
>>>>>>>>>> Greetings,
>>>>>>>>>>
>>>>>>>>>> The Async Monitor Deflation project is reaching the end game. 
>>>>>>>>>> I have no
>>>>>>>>>> changes planned for the project at this time so all that is 
>>>>>>>>>> left is code
>>>>>>>>>> review and any changes that results from those reviews.
>>>>>>>>>>
>>>>>>>>>> Carsten and Roman! Time for you guys to chime in again on the 
>>>>>>>>>> code reviews.
>>>>>>>>>>
>>>>>>>>>> I have attached the list of fixes from CR6 to CR7 instead of 
>>>>>>>>>> putting it
>>>>>>>>>> in the main body of this email.
>>>>>>>>>>
>>>>>>>>>> Main bug URL:
>>>>>>>>>>
>>>>>>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>>>>>>
>>>>>>>>>> The project is currently baselined on jdk-14+19.
>>>>>>>>>>
>>>>>>>>>> Here's the full webrev URL for those folks that want to see 
>>>>>>>>>> all of the
>>>>>>>>>> current Async Monitor Deflation code in one go (v2.07 full):
>>>>>>>>>>
>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/10-for-jdk14.v2.07.full 
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Some folks might want to see just what has changed since the 
>>>>>>>>>> last review
>>>>>>>>>> cycle so here's a webrev for that (v2.07 inc):
>>>>>>>>>>
>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/10-for-jdk14.v2.07.inc/ 
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> The OpenJDK wiki has been updated to match the 
>>>>>>>>>> CR7/v2.07/10-for-jdk14 changes:
>>>>>>>>>>
>>>>>>>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation 
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> The jdk-14+18 based v2.07 version of the patch has been thru 
>>>>>>>>>> Mach5 tier[1-8]
>>>>>>>>>> testing on Oracle's usual set of platforms. It has also been 
>>>>>>>>>> through my usual
>>>>>>>>>> set of stress testing on Linux-X64, macOSX and Solaris-X64 
>>>>>>>>>> with the addition
>>>>>>>>>> of Robbin's "MoCrazy 1024" test running in parallel with the 
>>>>>>>>>> other tests in
>>>>>>>>>> my lab.
>>>>>>>>>>
>>>>>>>>>> The jdk-14+19 based v2.07 version of the patch has been thru 
>>>>>>>>>> Mach5 tier[1-3]
>>>>>>>>>> test on Oracle's usual set of platforms. Mach5 tier[4-8] are 
>>>>>>>>>> in process.
>>>>>>>>>>
>>>>>>>>>> I did another round of SPECjbb2015 testing in Oracle's Aurora 
>>>>>>>>>> Performance lab
>>>>>>>>>> using using their tuned SPECjbb2015 Linux-X64 G1 configs:
>>>>>>>>>>
>>>>>>>>>>     - "base" is jdk-14+18
>>>>>>>>>>     - "v2.07" is the latest version and includes C2 
>>>>>>>>>> inc_om_ref_count() support
>>>>>>>>>>       on LP64 X64 and the new 
>>>>>>>>>> HandshakeAfterDeflateIdleMonitors option
>>>>>>>>>>     - "off" is with -XX:-AsyncDeflateIdleMonitors specified
>>>>>>>>>>     - "handshake" is with 
>>>>>>>>>> -XX:+HandshakeAfterDeflateIdleMonitors specified
>>>>>>>>>>
>>>>>>>>>>          hbIR           hbIR
>>>>>>>>>>     (max attempted)  (settled)  max-jOPS critical-jOPS runtime
>>>>>>>>>>     ---------------  ---------  -------- ------------- -------
>>>>>>>>>>            34282.00   30635.90  28831.30 20969.20 3841.30 base
>>>>>>>>>>            34282.00   30973.00  29345.80 21025.20 3964.10 v2.07
>>>>>>>>>>            34282.00   31105.60  29174.30 21074.00 3931.30 
>>>>>>>>>> v2.07_handshake
>>>>>>>>>>            34282.00   30789.70  27151.60 19839.10 3850.20 
>>>>>>>>>> v2.07_off
>>>>>>>>>>
>>>>>>>>>>     - The Aurora Perf comparison tool reports:
>>>>>>>>>>
>>>>>>>>>>         Comparison              max-jOPS critical-jOPS
>>>>>>>>>>         ---------------------- -------------------- 
>>>>>>>>>> --------------------
>>>>>>>>>>         base vs 2.07            +1.78% (s, p=0.000) +0.27% 
>>>>>>>>>> (ns, p=0.790)
>>>>>>>>>>         base vs 2.07_handshake  +1.19% (s, p=0.007) +0.58% 
>>>>>>>>>> (ns, p=0.536)
>>>>>>>>>>         base vs 2.07_off        -5.83% (ns, p=0.394) -5.39% 
>>>>>>>>>> (ns, p=0.347)
>>>>>>>>>>
>>>>>>>>>>         (s) - significant  (ns) - not-significant
>>>>>>>>>>
>>>>>>>>>>     - For historical comparison, the Aurora Perf comparision 
>>>>>>>>>> tool
>>>>>>>>>>         reported for v2.06 with a baseline of jdk-13+31:
>>>>>>>>>>
>>>>>>>>>>         Comparison              max-jOPS critical-jOPS
>>>>>>>>>>         ---------------------- -------------------- 
>>>>>>>>>> --------------------
>>>>>>>>>>         base vs 2.06            -0.32% (ns, p=0.345) +0.71% 
>>>>>>>>>> (ns, p=0.646)
>>>>>>>>>>         base vs 2.06_off        +0.49% (ns, p=0.292) -1.21% 
>>>>>>>>>> (ns, p=0.481)
>>>>>>>>>>
>>>>>>>>>>         (s) - significant  (ns) - not-significant
>>>>>>>>>>
>>>>>>>>>> Thanks, in advance, for any questions, comments or suggestions.
>>>>>>>>>>
>>>>>>>>>> Dan
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On 8/28/19 5:02 PM, Daniel D. Daugherty wrote:
>>>>>>>>>>> Greetings,
>>>>>>>>>>>
>>>>>>>>>>> The Async Monitor Deflation project has rebased to JDK14 so 
>>>>>>>>>>> it's time
>>>>>>>>>>> for our first code review in that new context!!
>>>>>>>>>>>
>>>>>>>>>>> I've been focused on changing the monitor list management 
>>>>>>>>>>> code to be
>>>>>>>>>>> lock-free in order to make SPECjbb2015 happier. Of course 
>>>>>>>>>>> with a change
>>>>>>>>>>> like that, it takes a while to chase down all the new and 
>>>>>>>>>>> wonderful
>>>>>>>>>>> races. At this point, I have the code back to the same 
>>>>>>>>>>> stability that
>>>>>>>>>>> I had with CR5/v2.05/8-for-jdk13.
>>>>>>>>>>>
>>>>>>>>>>> To lay the ground work for this round of review, I pushed 
>>>>>>>>>>> the following
>>>>>>>>>>> two fixes to jdk/jdk earlier today:
>>>>>>>>>>>
>>>>>>>>>>>     JDK-8230184 rename, whitespace, indent and comments 
>>>>>>>>>>> changes in preparation
>>>>>>>>>>>                 for lock free Monitor lists
>>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8230184
>>>>>>>>>>>
>>>>>>>>>>>     JDK-8230317 serviceability/sa/ClhsdbPrintStatics.java 
>>>>>>>>>>> fails after 8230184
>>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8230317
>>>>>>>>>>>
>>>>>>>>>>> I have attached the list of fixes from CR5 to CR6 instead of 
>>>>>>>>>>> putting
>>>>>>>>>>> in the main body of this email.
>>>>>>>>>>>
>>>>>>>>>>> Main bug URL:
>>>>>>>>>>>
>>>>>>>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>>>>>>>
>>>>>>>>>>> The project is currently baselined on jdk-14+11 plus the 
>>>>>>>>>>> fixes for
>>>>>>>>>>> JDK-8230184 and JDK-8230317.
>>>>>>>>>>>
>>>>>>>>>>> Here's the full webrev URL for those folks that want to see 
>>>>>>>>>>> all of the
>>>>>>>>>>> current Async Monitor Deflation code in one go (v2.06 full):
>>>>>>>>>>>
>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/9-for-jdk14.v2.06.full/ 
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> The primary focus of this review cycle is on the lock-free 
>>>>>>>>>>> Monitor List
>>>>>>>>>>> management changes so here's a webrev for just that patch 
>>>>>>>>>>> (v2.06c):
>>>>>>>>>>>
>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/9-for-jdk14.v2.06c.inc/ 
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> The secondary focus of this review cycle is on the bug fixes 
>>>>>>>>>>> that have
>>>>>>>>>>> been made since CR5/v2.05/8-for-jdk13 so here's a webrev for 
>>>>>>>>>>> just that
>>>>>>>>>>> patch (v2.06b):
>>>>>>>>>>>
>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/9-for-jdk14.v2.06b.inc/ 
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> The third and final bucket for this review cycle is the 
>>>>>>>>>>> rename, whitespace,
>>>>>>>>>>> indent and comments changes made in preparation for lock 
>>>>>>>>>>> free Monitor list
>>>>>>>>>>> management. Almost all of that was extracted into 
>>>>>>>>>>> JDK-8230184 for the
>>>>>>>>>>> baseline so this bucket now has just a few comment changes 
>>>>>>>>>>> relative to
>>>>>>>>>>> CR5/v2.05/8-for-jdk13. Here's a webrev for the remainder 
>>>>>>>>>>> (v2.06a):
>>>>>>>>>>>
>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/9-for-jdk14.v2.06a.inc/ 
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Some folks might want to see just what has changed since the 
>>>>>>>>>>> last review
>>>>>>>>>>> cycle so here's a webrev for that (v2.06 inc):
>>>>>>>>>>>
>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/9-for-jdk14.v2.06.inc/ 
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Last, but not least, some folks might want to see the code 
>>>>>>>>>>> before the
>>>>>>>>>>> addition of lock-free Monitor List management so here's a 
>>>>>>>>>>> webrev for
>>>>>>>>>>> that (v2.00 -> v2.05):
>>>>>>>>>>>
>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/9-for-jdk14.v2.05.inc/ 
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> The OpenJDK wiki will need minor updates to match the CR6 
>>>>>>>>>>> changes:
>>>>>>>>>>>
>>>>>>>>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation 
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> but that should only be changes to describe per-thread list 
>>>>>>>>>>> async monitor
>>>>>>>>>>> deflation being done by the ServiceThread.
>>>>>>>>>>>
>>>>>>>>>>> (I did update the OpenJDK wiki for the CR5 changes back on 
>>>>>>>>>>> 2019.08.14)
>>>>>>>>>>>
>>>>>>>>>>> This version of the patch has been thru Mach5 tier[1-8] 
>>>>>>>>>>> testing on
>>>>>>>>>>> Oracle's usual set of platforms. It has also been through my 
>>>>>>>>>>> usual set
>>>>>>>>>>> of stress testing on Linux-X64, macOSX and Solaris-X64.
>>>>>>>>>>>
>>>>>>>>>>> I did a bunch of SPECjbb2015 testing in Oracle's Aurora 
>>>>>>>>>>> Performance lab
>>>>>>>>>>> using using their tuned SPECjbb2015 Linux-X64 G1 configs. 
>>>>>>>>>>> This was using
>>>>>>>>>>> this patch baselined on jdk-13+31 (for stability):
>>>>>>>>>>>
>>>>>>>>>>>           hbIR           hbIR
>>>>>>>>>>>      (max attempted)  (settled)  max-jOPS critical-jOPS runtime
>>>>>>>>>>>      ---------------  ---------  -------- ------------- -------
>>>>>>>>>>>             34282.00   28837.20  27905.20 19817.40 3658.10 base
>>>>>>>>>>>             34965.70   29798.80  27814.90 19959.00 3514.60 
>>>>>>>>>>> v2.06d
>>>>>>>>>>>             34282.00   29100.70  28042.50 19577.00 3701.90 
>>>>>>>>>>> v2.06d_off
>>>>>>>>>>>             34282.00   29218.50  27562.80 19397.30 3657.60 
>>>>>>>>>>> v2.06d_ocache
>>>>>>>>>>>             34965.70   29838.30  26512.40 19170.60 3569.90 
>>>>>>>>>>> v2.05
>>>>>>>>>>>             34282.00   28926.10  27734.00 19835.10 3588.40 
>>>>>>>>>>> v2.05_off
>>>>>>>>>>>
>>>>>>>>>>> The "off" configs are with -XX:-AsyncDeflateIdleMonitors 
>>>>>>>>>>> specified and
>>>>>>>>>>> the "ocache" config is with 128 byte cache line sizes 
>>>>>>>>>>> instead of 64 byte
>>>>>>>>>>> cache lines sizes. "v2.06d" is the last set of changes that 
>>>>>>>>>>> I made before
>>>>>>>>>>> those changes were distributed into the "v2.06a", "v2.06b" 
>>>>>>>>>>> and "v2.06c"
>>>>>>>>>>> buckets for this review recycle.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Thanks, in advance, for any questions, comments or suggestions.
>>>>>>>>>>>
>>>>>>>>>>> Dan
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On 7/11/19 3:49 PM, Daniel D. Daugherty wrote:
>>>>>>>>>>>> Greetings,
>>>>>>>>>>>>
>>>>>>>>>>>> I've been focused on chasing down and fixing the rare test 
>>>>>>>>>>>> failures
>>>>>>>>>>>> that only pop up rarely. So this round is primarily fixes 
>>>>>>>>>>>> for races
>>>>>>>>>>>> with a few additional fixes that came from Karen's review 
>>>>>>>>>>>> of CR4.
>>>>>>>>>>>> Thanks Karen!
>>>>>>>>>>>>
>>>>>>>>>>>> I have attached the list of fixes from CR4 to CR5 instead 
>>>>>>>>>>>> of putting
>>>>>>>>>>>> in the main body of this email.
>>>>>>>>>>>>
>>>>>>>>>>>> Main bug URL:
>>>>>>>>>>>>
>>>>>>>>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>>>>>>>>
>>>>>>>>>>>> The project is currently baselined on jdk-13+29. This will 
>>>>>>>>>>>> likely be
>>>>>>>>>>>> the last JDK13 baseline for this project and I'll roll to 
>>>>>>>>>>>> the JDK14
>>>>>>>>>>>> (jdk/jdk) repo soon...
>>>>>>>>>>>>
>>>>>>>>>>>> Here's the full webrev URL:
>>>>>>>>>>>>
>>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/8-for-jdk13.full/ 
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Here's the incremental webrev URL:
>>>>>>>>>>>>
>>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/8-for-jdk13.inc/ 
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> I have not yet checked the OpenJDK wiki to see if it needs 
>>>>>>>>>>>> any updates
>>>>>>>>>>>> to match the CR5 changes:
>>>>>>>>>>>>
>>>>>>>>>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation 
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> (I did update the OpenJDK wiki for the CR4 changes back on 
>>>>>>>>>>>> 2019.06.26)
>>>>>>>>>>>>
>>>>>>>>>>>> This version of the patch has been thru Mach5 tier[1-3] 
>>>>>>>>>>>> testing on
>>>>>>>>>>>> Oracle's usual set of platforms. Mach5 tier[4-6] is running 
>>>>>>>>>>>> now and
>>>>>>>>>>>> Mach5 tier[78] will follow. I'll kick off the usual stress 
>>>>>>>>>>>> testing
>>>>>>>>>>>> on Linux-X64, macOSX and Solaris-X64 as those machines 
>>>>>>>>>>>> become available.
>>>>>>>>>>>> Since I haven't made any performance changes in this round, 
>>>>>>>>>>>> I'll only
>>>>>>>>>>>> be running SPECjbb2015 to gather the latest 
>>>>>>>>>>>> monitorinflation logs.
>>>>>>>>>>>>
>>>>>>>>>>>> Next up:
>>>>>>>>>>>>
>>>>>>>>>>>> - We're still seeing 4-5% lower performance with 
>>>>>>>>>>>> SPECjbb2015 on
>>>>>>>>>>>>   Linux-X64 and we've determined that some of that comes from
>>>>>>>>>>>>   contention on the gListLock. So I'm going to investigate 
>>>>>>>>>>>> removing
>>>>>>>>>>>>   the gListLock. Yes, another lock free set of changes is 
>>>>>>>>>>>> coming!
>>>>>>>>>>>> - Of course, going lock free often causes new races and new 
>>>>>>>>>>>> failures
>>>>>>>>>>>>   so that's a good reason for make those changes isolated 
>>>>>>>>>>>> in their
>>>>>>>>>>>>   own round (and not holding up CR5/v2.05/8-for-jdk13 
>>>>>>>>>>>> anymore).
>>>>>>>>>>>> - I finally have a potential fix for the Win* failure with
>>>>>>>>>>>> gc/g1/humongousObjects/TestHumongousClassLoader.java
>>>>>>>>>>>>   but I haven't run it through Mach5 yet so it'll be in the 
>>>>>>>>>>>> next round.
>>>>>>>>>>>> - Some RTM tests were recently re-enabled in Mach5 and I'm 
>>>>>>>>>>>> seeing some
>>>>>>>>>>>>   monitor related failures there. I suspect that I need to 
>>>>>>>>>>>> go take a
>>>>>>>>>>>>   look at the C2 RTM macro assembler code and look for 
>>>>>>>>>>>> things that might
>>>>>>>>>>>>   conflict if Async Monitor Deflation. If you're interested 
>>>>>>>>>>>> in that kind
>>>>>>>>>>>>   of issue, then see the macroAssembler_x86.cpp sanity 
>>>>>>>>>>>> check that I
>>>>>>>>>>>>   added in this round!
>>>>>>>>>>>>
>>>>>>>>>>>> Thanks, in advance, for any questions, comments or 
>>>>>>>>>>>> suggestions.
>>>>>>>>>>>>
>>>>>>>>>>>> Dan
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> On 5/26/19 8:30 PM, Daniel D. Daugherty wrote:
>>>>>>>>>>>>> Greetings,
>>>>>>>>>>>>>
>>>>>>>>>>>>> I have a fix for an issue that came up during performance 
>>>>>>>>>>>>> testing.
>>>>>>>>>>>>> Many thanks to Robbin for diagnosing the issue in his 
>>>>>>>>>>>>> SPECjbb2015
>>>>>>>>>>>>> experiments.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Here's the list of changes from CR3 to CR4. The list is a bit
>>>>>>>>>>>>> verbose due to the complexity of the issue, but the changes
>>>>>>>>>>>>> themselves are not that big.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Functional:
>>>>>>>>>>>>>   - Change SafepointSynchronize::is_cleanup_needed() from 
>>>>>>>>>>>>> calling
>>>>>>>>>>>>> ObjectSynchronizer::is_cleanup_needed() to calling
>>>>>>>>>>>>> ObjectSynchronizer::is_safepoint_deflation_needed():
>>>>>>>>>>>>>     - is_safepoint_deflation_needed() returns the result of
>>>>>>>>>>>>>       monitors_used_above_threshold() for safepoint based
>>>>>>>>>>>>>       monitor deflation (!AsyncDeflateIdleMonitors).
>>>>>>>>>>>>>     - For AsyncDeflateIdleMonitors, it only returns true if
>>>>>>>>>>>>>       there is a special deflation request, e.g., System.gc()
>>>>>>>>>>>>>       - This solves a bug where there are a bunch of Cleanup
>>>>>>>>>>>>>         safepoints that simply request async deflation which
>>>>>>>>>>>>>         keeps the async JavaThreads from making progress on
>>>>>>>>>>>>>         their async deflation work.
>>>>>>>>>>>>>   - Add AsyncDeflationInterval diagnostic option. 
>>>>>>>>>>>>> Description:
>>>>>>>>>>>>>       Async deflate idle monitors every so many 
>>>>>>>>>>>>> milliseconds when
>>>>>>>>>>>>>       MonitorUsedDeflationThreshold is exceeded (0 is off).
>>>>>>>>>>>>>   - Replace 
>>>>>>>>>>>>> ObjectSynchronizer::gOmShouldDeflateIdleMonitors() with
>>>>>>>>>>>>> ObjectSynchronizer::is_async_deflation_needed():
>>>>>>>>>>>>>     - is_async_deflation_needed() returns true when
>>>>>>>>>>>>>       is_async_cleanup_requested() is true or when
>>>>>>>>>>>>>       monitors_used_above_threshold() is true (but no more 
>>>>>>>>>>>>> often than
>>>>>>>>>>>>>       AsyncDeflationInterval).
>>>>>>>>>>>>>     - if AsyncDeflateIdleMonitors Service_lock->wait() now 
>>>>>>>>>>>>> waits for
>>>>>>>>>>>>>       at most GuaranteedSafepointInterval millis:
>>>>>>>>>>>>>       - This allows is_async_deflation_needed() to be 
>>>>>>>>>>>>> checked at
>>>>>>>>>>>>>         the same interval as GuaranteedSafepointInterval.
>>>>>>>>>>>>>         (default is 1000 millis/1 second)
>>>>>>>>>>>>>       - Once is_async_deflation_needed() has returned 
>>>>>>>>>>>>> true, it
>>>>>>>>>>>>>         generally cannot return true for 
>>>>>>>>>>>>> AsyncDeflationInterval.
>>>>>>>>>>>>>         This is to prevent async deflation from swamping the
>>>>>>>>>>>>>         ServiceThread.
>>>>>>>>>>>>>   - The ServiceThread still handles async deflation of the 
>>>>>>>>>>>>> global
>>>>>>>>>>>>>     in-use list and now it also marks JavaThreads for 
>>>>>>>>>>>>> async deflation
>>>>>>>>>>>>>     of their in-use lists.
>>>>>>>>>>>>>     - The ServiceThread will check for async deflation 
>>>>>>>>>>>>> work every
>>>>>>>>>>>>>       GuaranteedSafepointInterval.
>>>>>>>>>>>>>     - A safepoint can still cause the ServiceThread to 
>>>>>>>>>>>>> check for
>>>>>>>>>>>>>       async deflation work via is_async_deflation_requested.
>>>>>>>>>>>>>   - Refactor code from 
>>>>>>>>>>>>> ObjectSynchronizer::is_cleanup_needed() into
>>>>>>>>>>>>>     monitors_used_above_threshold() and remove 
>>>>>>>>>>>>> is_cleanup_needed().
>>>>>>>>>>>>>   - In addition to System.gc(), the VM_Exit VM op and the 
>>>>>>>>>>>>> final
>>>>>>>>>>>>>     VMThread safepoint now set the 
>>>>>>>>>>>>> is_special_deflation_requested
>>>>>>>>>>>>>     flag to reduce the in-use monitor population that is 
>>>>>>>>>>>>> reported by
>>>>>>>>>>>>> ObjectSynchronizer::log_in_use_monitor_details() at VM exit.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Test update:
>>>>>>>>>>>>>   - test/hotspot/gtest/oops/test_markOop.cpp is updated to 
>>>>>>>>>>>>> work with
>>>>>>>>>>>>>     AsyncDeflateIdleMonitors.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Collateral:
>>>>>>>>>>>>>   - Add/clarify/update some logging messages.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Cleanup:
>>>>>>>>>>>>>   - Updated comments based on Karen's code review.
>>>>>>>>>>>>>   - Change 'special cleanup' -> 'special deflation' and
>>>>>>>>>>>>>     'async cleanup' -> 'async deflation'.
>>>>>>>>>>>>>     - comment and function name changes
>>>>>>>>>>>>>   - Clarify MonitorUsedDeflationThreshold description;
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Main bug URL:
>>>>>>>>>>>>>
>>>>>>>>>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>>>>>>>>>
>>>>>>>>>>>>> The project is currently baselined on jdk-13+22.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Here's the full webrev URL:
>>>>>>>>>>>>>
>>>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/7-for-jdk13.full/ 
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Here's the incremental webrev URL:
>>>>>>>>>>>>>
>>>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/7-for-jdk13.inc/ 
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> I have not updated the OpenJDK wiki to reflect the CR4 
>>>>>>>>>>>>> changes:
>>>>>>>>>>>>>
>>>>>>>>>>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation 
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> The wiki doesn't say a whole lot about the async deflation 
>>>>>>>>>>>>> invocation
>>>>>>>>>>>>> mechanism so I have to figure out how to add that content.
>>>>>>>>>>>>>
>>>>>>>>>>>>> This version of the patch has been thru Mach5 tier[1-8] 
>>>>>>>>>>>>> testing on
>>>>>>>>>>>>> Oracle's usual set of platforms. My Solaris-X64 stress kit 
>>>>>>>>>>>>> run is
>>>>>>>>>>>>> running now. Kitchensink8H on product, fastdebug, and 
>>>>>>>>>>>>> slowdebug bits
>>>>>>>>>>>>> are running on Linux-X64, MacOSX and Solaris-X64. I still 
>>>>>>>>>>>>> have to run
>>>>>>>>>>>>> my stress kit on Linux-X64. I still have to run the 
>>>>>>>>>>>>> SPECjbb2015
>>>>>>>>>>>>> baseline and CR4 runs on Linux-X64, MacOSX and Solaris-X64.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Thanks, in advance, for any questions, comments or 
>>>>>>>>>>>>> suggestions.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Dan
>>>>>>>>>>>>>
>>>>>>>>>>>>> On 5/6/19 11:52 AM, Daniel D. Daugherty wrote:
>>>>>>>>>>>>>> Greetings,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I had some discussions with Karen about a race that was 
>>>>>>>>>>>>>> in the
>>>>>>>>>>>>>> ObjectMonitor::enter() code in CR2/v2.02/5-for-jdk13. 
>>>>>>>>>>>>>> This race was
>>>>>>>>>>>>>> theoretical and I had no test failures due to it. The fix 
>>>>>>>>>>>>>> is pretty
>>>>>>>>>>>>>> simple: remove the special case code for async deflation 
>>>>>>>>>>>>>> in the
>>>>>>>>>>>>>> ObjectMonitor::enter() function and rely solely on the 
>>>>>>>>>>>>>> ref_count
>>>>>>>>>>>>>> for ObjectMonitor::enter() protection.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> During those discussions Karen also floated the idea of 
>>>>>>>>>>>>>> using the
>>>>>>>>>>>>>> ref_count field instead of the contentions field for the 
>>>>>>>>>>>>>> Async
>>>>>>>>>>>>>> Monitor Deflation protocol. I decided to go ahead and 
>>>>>>>>>>>>>> code up that
>>>>>>>>>>>>>> change and I have run it through the usual stress and 
>>>>>>>>>>>>>> Mach5 testing
>>>>>>>>>>>>>> with no issues. It's also known as v2.03 (for those for 
>>>>>>>>>>>>>> with the
>>>>>>>>>>>>>> patches) and as webrev/6-for-jdk13 (for those with webrev 
>>>>>>>>>>>>>> URLs).
>>>>>>>>>>>>>> Sorry for all the names...
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Main bug URL:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The project is currently baselined on jdk-13+18.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Here's the full webrev URL:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/6-for-jdk13.full/ 
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Here's the incremental webrev URL:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/6-for-jdk13.inc/ 
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I have also updated the OpenJDK wiki to reflect the CR3 
>>>>>>>>>>>>>> changes:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation 
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> This version of the patch has been thru Mach5 tier[1-8] 
>>>>>>>>>>>>>> testing on
>>>>>>>>>>>>>> Oracle's usual set of platforms. My Solaris-X64 stress 
>>>>>>>>>>>>>> kit run had
>>>>>>>>>>>>>> no issues. Kitchensink8H on product, fastdebug, and 
>>>>>>>>>>>>>> slowdebug bits
>>>>>>>>>>>>>> had no failures on Linux-X64; MacOSX fastdebug and 
>>>>>>>>>>>>>> slowdebug and
>>>>>>>>>>>>>> Solaris-X64 release had the usual "Too large time diff" 
>>>>>>>>>>>>>> complaints.
>>>>>>>>>>>>>> 12 hour Inflate2 runs on product, fastdebug and slowdebug 
>>>>>>>>>>>>>> bits on
>>>>>>>>>>>>>> Linux-X64, MacOSX and Solaris-X64 had no failures. My 
>>>>>>>>>>>>>> Linux-X64
>>>>>>>>>>>>>> stress kit is running right now.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I've done the SPECjbb2015 baseline and CR3 runs. I need 
>>>>>>>>>>>>>> to gather
>>>>>>>>>>>>>> the results and analyze them.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Thanks, in advance, for any questions, comments or 
>>>>>>>>>>>>>> suggestions.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Dan
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> On 4/25/19 12:38 PM, Daniel D. Daugherty wrote:
>>>>>>>>>>>>>>> Greetings,
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I have a small but important bug fix for the Async 
>>>>>>>>>>>>>>> Monitor Deflation
>>>>>>>>>>>>>>> project ready to go. It's also known as v2.02 (for those 
>>>>>>>>>>>>>>> for with the
>>>>>>>>>>>>>>> patches) and as webrev/5-for-jdk13 (for those with 
>>>>>>>>>>>>>>> webrev URLs). Sorry
>>>>>>>>>>>>>>> for all the names...
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> JDK-8222295 was pushed to jdk/jdk two days ago so that 
>>>>>>>>>>>>>>> baseline patch
>>>>>>>>>>>>>>> is out of our hair.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Main bug URL:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> The project is currently baselined on jdk-13+17.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Here's the full webrev URL:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/5-for-jdk13.full/ 
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Here's the incremental webrev URL (JDK-8153224):
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/5-for-jdk13.inc/ 
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I still have to update the OpenJDK wiki to reflect the 
>>>>>>>>>>>>>>> CR2 changes:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation 
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> This version of the patch has been thru Mach5 tier[1-6] 
>>>>>>>>>>>>>>> testing on
>>>>>>>>>>>>>>> Oracle's usual set of platforms. Mach5 tier[7-8] is 
>>>>>>>>>>>>>>> running now.
>>>>>>>>>>>>>>> My stress kit is running on Solaris-X64 now. 
>>>>>>>>>>>>>>> Kitchensink8H is running
>>>>>>>>>>>>>>> now on product, fastdebug, and slowdebug bits on 
>>>>>>>>>>>>>>> Linux-X64, MacOSX
>>>>>>>>>>>>>>> and Solaris-X64. 12 hour Inflate2 runs are running now 
>>>>>>>>>>>>>>> on product,
>>>>>>>>>>>>>>> fastdebug and slowdebug bits on Linux-X64, MacOSX and 
>>>>>>>>>>>>>>> Solaris-X64.
>>>>>>>>>>>>>>> I'll start my my stress kit on Linux-X64 sometime on 
>>>>>>>>>>>>>>> Sunday (after
>>>>>>>>>>>>>>> my jdk-13+18 stress run is done).
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I'll do SPECjbb2015 baseline and CR2 runs after all the 
>>>>>>>>>>>>>>> stress
>>>>>>>>>>>>>>> testing is done.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks, in advance, for any questions, comments or 
>>>>>>>>>>>>>>> suggestions.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Dan
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> On 4/19/19 11:58 AM, Daniel D. Daugherty wrote:
>>>>>>>>>>>>>>>> Greetings,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I finally have CR1 for the Async Monitor Deflation 
>>>>>>>>>>>>>>>> project ready to
>>>>>>>>>>>>>>>> go. It's also known as v2.01 (for those for with the 
>>>>>>>>>>>>>>>> patches) and as
>>>>>>>>>>>>>>>> webrev/4-for-jdk13 (for those with webrev URLs). Sorry 
>>>>>>>>>>>>>>>> for all the
>>>>>>>>>>>>>>>> names...
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Main bug URL:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>>>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Baseline bug fixes URL:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>     JDK-8222295 more baseline cleanups from Async 
>>>>>>>>>>>>>>>> Monitor Deflation project
>>>>>>>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8222295
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> The project is currently baselined on jdk-13+15.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Here's the webrev for the latest baseline changes 
>>>>>>>>>>>>>>>> (JDK-8222295):
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/4-for-jdk13.8222295 
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Here's the full webrev URL (JDK-8153224 only):
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/4-for-jdk13.full/ 
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Here's the incremental webrev URL (JDK-8153224):
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/4-for-jdk13.inc/ 
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> So I'm looking for reviews for both JDK-8222295 and the 
>>>>>>>>>>>>>>>> latest version
>>>>>>>>>>>>>>>> of JDK-8153224...
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I still have to update the OpenJDK wiki to reflect the 
>>>>>>>>>>>>>>>> CR changes:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation 
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> This version of the patch has been thru Mach5 tier[1-3] 
>>>>>>>>>>>>>>>> testing on
>>>>>>>>>>>>>>>> Oracle's usual set of platforms. Mach5 tier[4-6] is 
>>>>>>>>>>>>>>>> running now and
>>>>>>>>>>>>>>>> Mach5 tier[78] will be run later today. My stress kit 
>>>>>>>>>>>>>>>> on Solaris-X64
>>>>>>>>>>>>>>>> is running now. Linux-X64 stress testing will start on 
>>>>>>>>>>>>>>>> Sunday. I'm
>>>>>>>>>>>>>>>> planning to do Kitchensink runs, SPECjbb2015 runs and 
>>>>>>>>>>>>>>>> my monitor
>>>>>>>>>>>>>>>> inflation stress tests on Linux-X64, MacOSX and 
>>>>>>>>>>>>>>>> Solaris-X64.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thanks, in advance, for any questions, comments or 
>>>>>>>>>>>>>>>> suggestions.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Dan
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On 3/24/19 9:57 AM, Daniel D. Daugherty wrote:
>>>>>>>>>>>>>>>>> Greetings,
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Welcome to the OpenJDK review thread for my port of 
>>>>>>>>>>>>>>>>> Carsten's work on:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>     JDK-8153224 Monitor deflation prolong safepoints
>>>>>>>>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8153224
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Here's a link to the OpenJDK wiki that describes my port:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> https://wiki.openjdk.java.net/display/HotSpot/Async+Monitor+Deflation 
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Here's the webrev URL:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> http://cr.openjdk.java.net/~dcubed/8153224-webrev/3-for-jdk13/ 
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Here's a link to Carsten's original webrev:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> http://cr.openjdk.java.net/~cvarming/monitor_deflate_conc/0/ 
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Earlier versions of this patch have been through 
>>>>>>>>>>>>>>>>> several rounds of
>>>>>>>>>>>>>>>>> preliminary review. Many thanks to Carsten, Coleen, 
>>>>>>>>>>>>>>>>> Robbin, and
>>>>>>>>>>>>>>>>> Roman for their preliminary code review comments. A 
>>>>>>>>>>>>>>>>> very special
>>>>>>>>>>>>>>>>> thanks to Robbin and Roman for building and testing 
>>>>>>>>>>>>>>>>> the patch in
>>>>>>>>>>>>>>>>> their own environments (including specJBB2015).
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> This version of the patch has been thru Mach5 
>>>>>>>>>>>>>>>>> tier[1-8] testing on
>>>>>>>>>>>>>>>>> Oracle's usual set of platforms. Earlier versions have 
>>>>>>>>>>>>>>>>> been run
>>>>>>>>>>>>>>>>> through my stress kit on my Linux-X64 and Solaris-X64 
>>>>>>>>>>>>>>>>> servers
>>>>>>>>>>>>>>>>> (product, fastdebug, slowdebug).Earlier versions have 
>>>>>>>>>>>>>>>>> run Kitchensink
>>>>>>>>>>>>>>>>> for 12 hours on MacOSX, Linux-X64 and Solaris-X64 
>>>>>>>>>>>>>>>>> (product, fastdebug
>>>>>>>>>>>>>>>>> and slowdebug). Earlier versions have run my monitor 
>>>>>>>>>>>>>>>>> inflation stress
>>>>>>>>>>>>>>>>> tests for 12 hours on MacOSX, Linux-X64 and 
>>>>>>>>>>>>>>>>> Solaris-X64 (product,
>>>>>>>>>>>>>>>>> fastdebug and slowdebug).
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> All of the testing done on earlier versions will be 
>>>>>>>>>>>>>>>>> redone on the
>>>>>>>>>>>>>>>>> latest version of the patch.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Thanks, in advance, for any questions, comments or 
>>>>>>>>>>>>>>>>> suggestions.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Dan
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> P.S.
>>>>>>>>>>>>>>>>> One subtest in 
>>>>>>>>>>>>>>>>> gc/g1/humongousObjects/TestHumongousClassLoader.java
>>>>>>>>>>>>>>>>> is currently failing in -Xcomp mode on Win* only. I've 
>>>>>>>>>>>>>>>>> been trying
>>>>>>>>>>>>>>>>> to characterize/analyze this failure for more than a 
>>>>>>>>>>>>>>>>> week now. At
>>>>>>>>>>>>>>>>> this point I'm convinced that Async Monitor Deflation 
>>>>>>>>>>>>>>>>> is aggravating
>>>>>>>>>>>>>>>>> an existing bug. However, I plan to have a better 
>>>>>>>>>>>>>>>>> handle on that
>>>>>>>>>>>>>>>>> failure before these bits are pushed to the jdk/jdk repo.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>



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