disable JDK-8061553 optimization while JDK-8077392 is resolved (8079359)

[Daniel D. Daugherty]

Thanks!

Dan


On 5/5/15 1:12 PM, Alejandro E Murillo wrote:
> Fine with me
> Alejandro
>
> On 5/5/2015 11:06 AM, Daniel D. Daugherty wrote:
>> Greetings,
>>
>> The following bug fix:
>>
>>     JDK-8061553 Contended Locking fast enter bucket
>>
>> is causing intermittent hangs in JDK9-dev testing. That hang is
>> being tracked by the following bug:
>>
>>     JDK-8077392 Stream fork/join tasks occasionally fail to complete
>>
>> In order to make the JDK9-dev nightly testing more stable,
>> I would like to disable the JDK-8061553 optimization until
>> I resolve JDK-8077392.
>>
>> I'm targeting this fix for JDK9-dev directly instead of going
>> through the usual process of:
>>
>>     push fix -> RT_Baseline
>>     RT_Baseline -> Main_Baseline
>>     Main_Baseline -> JDK9-dev
>>
>> in order to get JDK9-dev stable more quickly.
>>
>> Lana and Alejandro, please let me know if either of you has
>> a problem with this out-of-band work around.
>>
>> Dan
>>
>>
>>
>> -------- Original Message --------
>> Subject: 	[JBS] (JDK-8079359) disable JDK-8061553 optimization while 
>> JDK-8077392 is resolved
>> Date: 	Tue, 5 May 2015 16:59:40 +0000 (UTC)
>> From: 	Daniel Daugherty (JBS) <do-not-reply at openjdk.java.net>
>> To: 	daniel.daugherty at oracle.com
>>
>>
>>
>> Daniel Daugherty 
>> <https://bugs.openjdk.java.net/secure/ViewProfile.jspa?name=dcubed> 
>> started work on Bug JDK-8079359 
>> <https://bugs.openjdk.java.net/browse/JDK-8079359>
>> *disable JDK-8061553 optimization while JDK-8077392 is resolved* 
>> <https://bugs.openjdk.java.net/browse/JDK-8079359>
>>
>>
>> 	
>> Here is the proposed change:
>>
>> $ hg diff
>> diff -r a0df4738688e src/share/vm/runtime/sharedRuntime.cpp
>> --- a/src/share/vm/runtime/sharedRuntime.cpp Sat May 02 00:16:29 2015 
>> -0700
>> +++ b/src/share/vm/runtime/sharedRuntime.cpp Tue May 05 09:57:09 2015 
>> -0700
>> @@ -1793,7 +1793,9 @@ JRT_END
>>
>>  // Handles the uncommon case in locking, i.e., contention or an 
>> inflated lock.
>>  JRT_BLOCK_ENTRY(void, 
>> SharedRuntime::complete_monitor_locking_C(oopDesc* _obj, BasicLock* 
>> lock, JavaThread* thread))
>> - if (!SafepointSynchronize::is_synchronizing()) {
>> + // Disable ObjectSynchronizer::quick_enter() in default config
>> + // until JDK-8077392 
>> <https://bugs.openjdk.java.net/browse/JDK-8077392> is resolved.
>> + if ((SyncFlags & 256) != 0 && 
>> !SafepointSynchronize::is_synchronizing()) {
>>      // Only try quick_enter() if we're not trying to reach a safepoint
>>      // so that the calling thread reaches the safepoint more quickly.
>>      if (ObjectSynchronizer::quick_enter(_obj, thread, lock)) return;
>> *Change By:* 	Daniel Daugherty 
>> <https://bugs.openjdk.java.net/secure/ViewProfile.jspa?name=dcubed> 
>> (2015-05-05 09:57)
>> *Status:* 	Open In Progress
>> *Understanding:* 	Cause Known
>>
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>>
>>
>
> -- 
> Alejandro