Pls review 7091418: FX priority class from Solaris should be available to JVM

Paul Hohensee paul.hohensee at oracle.com
Mon Jan 23 12:59:57 PST 2012


Thanks!

paul

On 1/23/12 3:46 PM, charlie hunt wrote:
>  Looks good.
>
> hths,
>
> charlie ...
>
> On 01/23/12 01:26 PM, Paul Hohensee wrote:
>> I've got one review (from a Reviewer), need another (doesn't have to
>> be a Reviewer).
>>
>> Thanks,
>>
>> Paul
>>
>> On 1/20/12 12:13 PM, Paul Hohensee wrote:
>>> Webrev here
>>>
>>> http://cr.openjdk.java.net/~phh/7091418.00/
>>>
>>> This change defines a new Java pseudo-priority called 
>>> CriticalPriority, just
>>> above MaxPriority.  Compiler threads, the CMS background thread, and
>>> Java threads can have the os equivalent of this priority.  On 
>>> Solaris, this is
>>> the FX/60 scheduling class/priority.  On other platforms, it's the same
>>> as MaxPriority's os priority.
>>>
>>> There are 3 new command line switches, all gated by 
>>> UseExperimentalVMOptions.
>>>
>>> -XX:+UseCriticalJavaThreadPriority
>>>
>>> Maps Java MAX_PRIORITY to critical priority.
>>>
>>> -XX:+UseCriticalCompilerThreadPriority
>>>
>>> All compiler threads run at critical priority.
>>>
>>> -XX:+UseCriticalCMSThreadPriority
>>>
>>> The CMS background thread runs at critical priority.
>>>
>>> On Solaris, one must in addition use -XX:+UseThreadPriorities to use 
>>> native
>>> priorities at all.  Otherwise, Hotspot just accepts whatever Solaris 
>>> decides.
>>>
>>> Before this change, the Solaris implementation could only change 
>>> priorities
>>> within the process scheduling class.  It didn't change scheduling 
>>> classes on
>>> a per-thread basis.  I added that capability and used it for the 
>>> critical thread
>>> work.  I also fixed a bug where we were using thr_setprio() to save the
>>> original native priority during thread creation and reading it back 
>>> when
>>> the thread started via thr_getprio().  Since thr_setprio() can 
>>> change the
>>> user-supplied priority, this resulted in an unintended (lower) priority
>>> being used.
>>>
>>> Thanks,
>>>
>>> Paul
>>>
>
>


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