[8u] RFR 8248214: Add paddings for TaskQueueSuper to reduce false-sharing cache contention

[Zhengyu Gu]

On 10/26/20 1:15 PM, Hohensee, Paul wrote:
> Lgtm.

Thanks, Paul.

-Zhengyu

> 
> Paul
> 
> On 10/26/20, 6:19 AM, "jdk8u-dev on behalf of Zhengyu Gu" <jdk8u-dev-retn at openjdk.java.net on behalf of zgu at redhat.com> wrote:
> 
>      I would like to backport this patch to OpendJDK 8u for parity with
>      Oracle 8u281.
> 
>      The original patch does not apply cleanly.
> 
>      There is a conflict on copyright year of taskqueue.hpp
> 
>      - * Copyright (c) 2001, 2018, Oracle and/or its affiliates. All rights
>      reserved.
>      + * Copyright (c) 2001, 2020, Oracle and/or its affiliates. All rights
>      reserved.
> 
>      Besides, 8u does not have DEFINE_PAD_MINUS_SIZE macro, which is
>      introduced by JDK-8049737, that is used to pad the variable. This patch
>      imported the macro from 11u.
> 
>      The original bug: https://bugs.openjdk.java.net/browse/JDK-8248214
>      The original patch:
>      https://hg.openjdk.java.net/jdk-updates/jdk11u/rev/08c734477683
> 
> 
>      8u webrev: http://cr.openjdk.java.net/~zgu/JDK-8248214-8u/webrev.00/
> 
> 
>      Thanks,
> 
>      -Zhengyu
> 
>