[Patch] ParallelGC: Improve AlwaysPreTouch with multiple threads

[stefan.johansson at oracle.com]

Hi Amit,

A short heads up =)

We are in the middle of transitioning OpenJDK to git and GitHub, see JEP 
369 [1]. We will not have time to complete this review before the move 
takes place. Instead it will have to be restarted using GitHub. An 
introduction and great source of information on how to get started with 
the new workflow can be found on the project Skara wiki [2].

The move is scheduled for tomorrow [3], so starting next week you should 
be able to create your own PR on GitHub for this change.

Thanks,
Stefan

[1] https://openjdk.java.net/jeps/369
[2] https://wiki.openjdk.java.net/display/SKARA/
[3] https://mail.openjdk.java.net/pipermail/jdk-dev/2020-August/004588.html


On 2020-08-25 07:28, amith pawar wrote:
> Hello everyone,
> 
> Looks like due to some issue nobody received my patch earlier sent to 
> this group. Stefan created Webrev and JBS for this patch. Thanks Stefan 
> for all your help.
> 
> This patch improve ParallelGC pretouch time similar to other GCs.
> 
> Please reivew this change.
> 
> Thanks,
> Amit
> 
> 
> On Tue, Aug 25, 2020 at 3:04 AM <stefan.johansson at oracle.com 
> <mailto:stefan.johansson at oracle.com>> wrote:
> 
>     Hi Amit,
> 
>     I've now created a webrev and JBS entry for your proposal. Here are the
>     links:
>     Webrev:
>     http://cr.openjdk.java.net/~sjohanss/sponsor/amit.pawar/8252221/00/
>     JBS: https://bugs.openjdk.java.net/browse/JDK-8252221
> 
>     Thanks,
>     Stefan
> 
>     On 2020-08-21 13:48, stefan.johansson at oracle.com
>     <mailto:stefan.johansson at oracle.com> wrote:
>      > Hi Amit,
>      >
>      > Now the patch made it through =)
>      >
>      > Me or somebody else from the GC-team will provide feedback once
>     we find
>      > time to look at the patch.
>      >
>      > Thanks for reaching out,
>      > Stefan
>      >
>      > On 2020-08-21 13:39, amith pawar wrote:
>      >> Hi Stefan,
>      >>
>      >> Thanks for replying. First time got rejected and then resent it
>     after
>      >> subscribing to the group. Not sure how this happened.
>      >>
>      >> I am attaching again. Please do check.
>      >>
>      >> Thanks,
>      >> Amit Pawar
>      >>
>      >> On Fri, Aug 21, 2020 at 1:29 PM <stefan.johansson at oracle.com
>     <mailto:stefan.johansson at oracle.com>
>      >> <mailto:stefan.johansson at oracle.com
>     <mailto:stefan.johansson at oracle.com>>> wrote:
>      >>
>      >>     Hi Amit,
>      >>
>      >>     Your patch did not make it to the list. It might have been
>     stripped.
>      >>     Are
>      >>     you subscribed to the list? That might be required to attach
>     patches.
>      >>
>      >>     Thanks,
>      >>     Stefan
>      >>
>      >>     On 2020-08-20 19:33, amith pawar wrote:
>      >>      >   Hi,
>      >>      >
>      >>      > Currently AlwaysPreTouch for ParallelGC is done with a single
>      >>     thread and
>      >>      > this attached patch converts it to multithreaded similar
>     to other
>      >>     GCs.
>      >>      >
>      >>      > All JTREG tests passed without new failures.
>      >>      >
>      >>      > Time taken for pretouch on EPYC server with 1TB memory
>     and 128
>      >>     threads
>      >>      > Before fix: ~107 s
>      >>      > After fix   :  ~14 s
>      >>      >
>      >>      > Please review this attached patch and give your feedback.
>      >>      >
>      >>      > Thanks,
>      >>      > Amit Pawar
>      >>      >
>      >>
>      >>
>      >>
>      >> --
>      >> With best regards,
>      >> amit pawar
> 
> 
> 
> -- 
> With best regards,
> amit pawar