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

Daniel D. Daugherty daniel.daugherty at oracle.com
Tue Jun 2 02:55:05 UTC 2020


Hi David,

On 6/1/20 10:09 PM, David Holmes wrote:
> Hi Dan,
>
> On 2/06/2020 10:30 am, Daniel D. Daugherty wrote:
>> 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.
>
> Right - I grok the race in general, it was just reasoning about all 
> the potential transitions for _contentions that was unclear but ...
>
>> The diagram shows the progression of contentions values:
>>
>> - ObjectMonitor box 1 shows contentions == 1 because T-enter incremented
>>    the contentions field
>
> ... I was overlooking that _contentions==1 before we hit the code I 
> was querying. So that reduces the state space somewhat and ...
>
>> - 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.
>
> ... right, I can stare at the existing diagram and work out the 
> potential orderings of the changes to _contentions.
>
>> 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.
>
> That is fine - thanks.
>
>>>
>>> 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.
>
> :) Thumbs up.

Thanks!


>
>>
>>> 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!!
>
> Thanks for all your diligence with the project. It's an extremely 
> complex piece of work to take through to delivery.

You are quite welcome! The project has yielded a bunch of improvements
to the ObjectMonitor subsystem and has been a worthwhile effort.

Dan

>
> Cheers,
> David
>
>> 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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