[8u] RFR for backport of JDK-8158012: Use SW prefetch instructions instead of BIS for allocation prefetches on SPARC Core C4

[David Holmes]

On 29/08/2017 5:54 PM, Muthusamy Chinnathambi wrote:
> Thanks David and Poonam for the review.
> 
> Please find the updated webrev with copyright and punctuation changes at http://cr.openjdk.java.net/~shshahma/Muthu/8158012/webrev.02/

Please add a period after "style 3" at:

vm_version_sparc.cpp:

!           // On CoreS4 processors use prefetch instruction
!           // to avoid partial RAW issue, also use prefetch style 3

Thanks. No need for updated webrev.

David

> Regards,
> Muthusamy C
> 
> -----Original Message-----
> From: David Holmes
> Sent: Tuesday, August 29, 2017 11:34 AM
> To: Poonam Parhar <poonam.bajaj at oracle.com>; Muthusamy Chinnathambi <muthusamy.chinnathambi at oracle.com>; Vladimir Kozlov <vladimir.kozlov at oracle.com>; hotspot-dev at openjdk.java.net
> Subject: Re: [8u] RFR for backport of JDK-8158012: Use SW prefetch instructions instead of BIS for allocation prefetches on SPARC Core C4
> 
> On 29/08/2017 11:37 AM, Poonam Parhar wrote:
>> Hello Muthu,
>>
>> The changes look good. One minor nit - please remove '.' at the end of the comment at line 144 in vm_version_sparc.cpp:
>>
>> 144           // Use BIS instruction for TLAB allocation prefetch.
>> 145           // on Niagara plus processors other than those based on CoreS4
> 
> I think it should be moved to the end of L145, as we now have a longer
> sentence.
> 
> Cheers,
> David
> 
>> Also, please update the copyright year for both the files.
>>
>> Thanks,
>> Poonam
>>
>>> -----Original Message-----
>>> From: Muthusamy Chinnathambi
>>> Sent: Tuesday, July 25, 2017 2:14 AM
>>> To: Vladimir Kozlov; hotspot-dev at openjdk.java.net
>>> Subject: RE: [8u] RFR for backport of JDK-8158012: Use SW prefetch
>>> instructions instead of BIS for allocation prefetches on SPARC Core C4
>>>
>>> May I please get a second review for this change.
>>>
>>> Thanks,
>>> Muthusamy C
>>>
>>> -----Original Message-----
>>> From: Vladimir Kozlov
>>> Sent: Monday, July 24, 2017 9:52 PM
>>> To: Muthusamy Chinnathambi <muthusamy.chinnathambi at oracle.com>;
>>> hotspot-dev at openjdk.java.net
>>> Subject: Re: [8u] RFR for backport of JDK-8158012: Use SW prefetch
>>> instructions instead of BIS for allocation prefetches on SPARC Core C4
>>>
>>> This looks good.
>>>
>>> Thanks,
>>> Vladimir
>>>
>>> On 7/23/17 11:56 PM, Muthusamy Chinnathambi wrote:
>>>> Hi Vladimir,
>>>>
>>>> Thanks for the review.
>>>> Please find the updated webrev at
>>>> http://cr.openjdk.java.net/~shshahma/Muthu/8158012/webrev.01/
>>>>
>>>> Regards,
>>>> Muthusamy C
>>>>
>>>> -----Original Message-----
>>>> From: Vladimir Kozlov
>>>> Sent: Friday, July 21, 2017 4:38 AM
>>>> To: Muthusamy Chinnathambi <muthusamy.chinnathambi at oracle.com>;
>>>> hotspot-dev at openjdk.java.net
>>>> Subject: Re: [8u] RFR for backport of JDK-8158012: Use SW prefetch
>>>> instructions instead of BIS for allocation prefetches on SPARC Core
>>> C4
>>>>
>>>> The indent for next comment line in vm_version_sparc.cpp is off:
>>>>
>>>> // Use BIS instr
>>>>
>>>> And AllocatePrefetchStyle set to 3 should be outside new check
>>> (should
>>>> be set for both cases). In JDK 9 there is following code which set it
>>>> for AllocatePrefetchInstr == 1 which JDK8 does not have:
>>>>
>>>>
>>> http://hg.openjdk.java.net/jdk9/jdk9/hotspot/file/eebdc7acebd4/src/cpu
>>>> /sparc/vm/vm_version_sparc.cpp#l126
>>>>
>>>> thanks,
>>>> Vladimir
>>>>
>>>> On 7/20/17 12:24 AM, Muthusamy Chinnathambi wrote:
>>>>> Hi,
>>>>>
>>>>> Please review the backport of bug: "JDK-8158012: Use SW prefetch
>>>>> instructions instead of BIS for allocation prefetches on SPARC Core
>>>>> C4" to jdk8u-dev
>>>>>
>>>>> Please note that this is not a clean backport due to conflict in
>>> comments and slight re-order of code.
>>>>>
>>>>>
>>>>> Webrev:
>>> http://cr.openjdk.java.net/~shshahma/Muthu/8158012/webrev.00/
>>>>> jdk9 bug: https://bugs.openjdk.java.net/browse/JDK-8158012
>>>>> Original patch pushed to jdk9:
>>>>> http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/eebdc7acebd4
>>>>>
>>>>> Test:  Ran jprt and jtreg.
>>>>>
>>>>> Regards,
>>>>> Muthusamy C
>>>>>