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

[Daniel D. Daugherty]

The URL was put in there by the JBS email sender...

Here's the real diff:

$ cat 8079359.diff.txt.00
diff -r a0df4738688e src/share/vm/runtime/sharedRuntime.cpp
--- a/src/share/vm/runtime/sharedRuntime.cpp
+++ b/src/share/vm/runtime/sharedRuntime.cpp
@@ -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 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;


Dan

On 5/5/15 1:00 PM, Dmitry Samersoff wrote:
> Dan,
>
> Please, don't insert URL
> <https://bugs.openjdk.java.net/browse/JDK-8077392> in the code. I think
> just a CR number is enough.
>
> -Dmitry
>
> On 2015-05-05 20:06, 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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>>
>>
>>
>