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

[Alejandro E Murillo]

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