linux os processor optimizations for OpenJDK GC performance enhancement

[David Holmes]

Hi Ramki,

On 19/04/2017 12:34 AM, Ram Krishnan wrote:
> Please find detailed proposal below, looking forward to your comments.
>
> "Minimize application tail latency using cache-partitioning-aware G1GC" --
> https://docs.google.com/document/d/1rPMG4XUiE7cUEOogW1z5tBbBZTclOWyg0arhuycXN94/edit

All contributions to OpenJDK need to be hosted on OpenJDK infrastructure 
not on external systems like the above.

Also I can not see you listed as an OCA signatory. Are you an OpenJDK 
contributor?

Thanks,
David
-----

> Thanks,
> Ramki
>
> On Thu, Apr 13, 2017 at 11:04 PM, Bernd Eckenfels <ecki at zusammenkunft.net>
> wrote:
>
>> Maybe it would be better to concentrate the processor optimizations on
>> accessors and barrriers without introducing a completely new GC
>> architecture. I can imagine that especially in the area of NUMA, TLAB, huge
>> pages, cache consistency and possibly MMX extensions there is some
>> potential.
>>
>> Abandoning the global STW - while it seems like a pretty powerful change -
>> is I guess not a good starter exercise. Especially since it is not only a
>> question of mutator threads.
>>
>> Gruss
>> Bernd
>> --
>> http://bernd.eckenfels.net
>> ------------------------------
>> *From:* hotspot-gc-dev <hotspot-gc-dev-bounces at openjdk.java.net> on
>> behalf of Ram Krishnan <ramkri123 at gmail.com>
>> *Sent:* Friday, April 14, 2017 6:36:27 AM
>> *To:* Asif Qamar; Andrew Haley; hotspot-gc-dev at openjdk.java.net
>> *Subject:* Re: linux os processor optimizations for OpenJDK GC
>> performance enhancement
>>
>> Thanks Andrew.
>>
>> ​>>Surely there is: a thread could have its TLAB allocated from a region
>>>> local to that socket (or core), and the GC thread for that region
>>>> could run on the same socket.  It only works for young gen, but that's
>>>> a lot of the problem.
>>
>> A clarification -- does the TLAB allocation apply to tenured space also?
>> If not, the above would work only for young gen cases where there is no
>> promotion to tenured right?
>>
>> Thanks,
>> Ramki
>>
>> On Thu, Apr 13, 2017 at 12:55 PM, Ram Krishnan <ramkri123 at gmail.com>
>> wrote:
>>
>>>
>>> ---------- Forwarded message ----------
>>> From:
>>> ​​
>>> Andrew Haley <aph at redhat.com>
>>> Date: Thu, Apr 13, 2017 at 9:52 AM
>>> Subject: Re: linux os processor optimizations for OpenJDK GC performance
>>> enhancement
>>> To:
>>> ​​
>>> hotspot-gc-dev at openjdk.java.net
>>>
>>>
>>> On 13/04/17 16:33, Kim Barrett wrote:
>>>> An application thread may touch memory in any region; there is no
>>>> notion of a thread being "scoped" to a specific set of regions. While
>>>> it might happen that a thread would only touch regions not being
>>>> worked on by the collector, there is no a priori way to know that.
>>>
>>> ​​
>>> Surely there is: a thread could have its TLAB allocated from a region
>>> local to that socket (or core), and the GC thread for that region
>>> could run on the same socket.  It only works for young gen, but that's
>>> a lot of the problem.
>>>
>>> Andrew.
>>>
>>>
>>>
>>>
>>> --
>>> Thanks,
>>> Ramki
>>>
>>
>>
>>
>> --
>> Thanks,
>> Ramki
>>
>
>
>