Backports to jdk11u and jdk17u

Tue Jan 17 01:34:11 UTC 2023

>I expect to initiate the backport in a dedicated openjdk/riscv-port-jdk17u repository for exactly that. Until the riscv port is considered very stable and performant, we likely want to keep it in a separate repository. When stable, we can work with the relevant maintainers of jdk8u, jdk11u and jdk17u for possible integrations.

Agree. It’s a good idea to make a stable backport before upstream to jdk17u.
We discussed with Goetz this May [1], and I have an backport version [2] with more changes in shared code protected by #ifdef RISCV that would meet Goetz’s concerns.
I can contribute the initial backport when the riscv-port-jdk17u repo is ready, and we can backport patches we think are necessary until it is ready to go to jdk17u-dev.

Do you think that’s okay?

[1] https://mail.openjdk.org/pipermail/jdk-updates-dev/2022-May/014396.html
[2] https://github.com/yadongw/jdk17u-dev/tree/backport-riscv-port-v5

From: Ludovic Henry [mailto:ludovic at rivosinc.com]
Sent: Monday, January 16, 2023 11:37 PM
To: 章翔 <zhangxiang at iscas.ac.cn>
Cc: yangfei at iscas.ac.cn; riscv-port-dev at openjdk.org; wangyadong (E) <yadonn.wang at huawei.com>; jdk-updates-dev at openjdk.java.net
Subject: Re: Re: Backports to jdk11u and jdk17u

> However there is one big difference between general jdk17u and riscv secific one: while jdk17u accepts only bug fixes and minor perf improvements, the riscv-port-jdk17u will have to accept larger patches: as risc-v port is far from being perfect so far, performance-wise is worse than arm64 port.

I expect to initiate the backport in a dedicated openjdk/riscv-port-jdk17u repository for exactly that. Until the riscv port is considered very stable and performant, we likely want to keep it in a separate repository. When stable, we can work with the relevant maintainers of jdk8u, jdk11u and jdk17u for possible integrations.

> In fact, there were some discussions before on the list about the backporting work [1].

I missed this one, thanks for pointing it out.

> I'm Xiang Zhang from the Institute of Software, Chinese Academy of Sciences. I'm backporting jdk8u for RISC-V support. Here is my development repository:
> https://github.com/zhangxiang-plct/jdk8u

If there is a riscv-port-jdk8u project, would you be interested to contribute there directly?

In the meantime, I'll contact skara-dev to figure out what it would take to create the riscv-port-jdk11u and riscv-port-jdk17u repositories.

Thanks,
Ludovic

On Mon, Jan 16, 2023 at 2:33 PM 章翔 <zhangxiang at iscas.ac.cn<mailto:zhangxiang at iscas.ac.cn>> wrote:
Hello,
I'm Xiang Zhang from the Institute of Software, Chinese Academy of Sciences. I'm backporting jdk8u for RISC-V support. Here is my development repository:
https://github.com/zhangxiang-plct/jdk8u
The current branch for template interpreter backporting is:
https://github.com/zhangxiang-plct/jdk8u/tree/Fix_javac-temp
As far as the current progress is concerned, the interpreter has been successfully ported.
For example, I can successfully run "Hello World" under -Xint.
I am currently testing benchmark workloads like dacapo and SPECjvm2008.
My next step is to backport C1&C2 and I'm debugging related code for porting C1&C2.

Thank you,
Xiang Zhang

> -----原始邮件-----
> 发件人: yangfei at iscas.ac.cn<mailto:yangfei at iscas.ac.cn>
> 发送时间: 2023-01-16 19:31:29 (星期一)
> 收件人: "Ludovic Henry" <ludovic at rivosinc.com<mailto:ludovic at rivosinc.com>>
> 抄送: riscv-port-dev at openjdk.org<mailto:riscv-port-dev at openjdk.org>, yadonn.wang at huawei.com<mailto:yadonn.wang at huawei.com>, zhangxiang at iscas.ac.cn<mailto:zhangxiang at iscas.ac.cn>
> 主题: Re: Backports to jdk11u and jdk17u
>
> Hi,
>
> In fact, there were some discussions before on the list about the backporting work [1].
> AFAIK, developers from Huawei already have workable versions of jdk11u & jdk17u on Linux/RISCV platform.
> So I guess the rest of the work should be upstreaming. I think Yadong Wang from Huawei should have more details about that?
>
> Regarding backports to jdk8u, I also wonder whether users are interested to deploy jdk8u on riscv.
> Xiang Zhang from ISCAS (Institute of Software, Chinese Academy of Sciences) is currently working on backporting to jdk8u
> and has achieved some progress. But let me try to get the people involved in this discussion and see.
>
> Thanks,
> Fei
>
> [1] https://mail.openjdk.org/pipermail/jdk-updates-dev/2022-May/014391.html
>
>
> -----Original Messages-----
> From:"Ludovic Henry" <ludovic at rivosinc.com<mailto:ludovic at rivosinc.com>>
> Sent Time:2023-01-16 18:04:22 (Monday)
> To: riscv-port-dev at openjdk.org<mailto:riscv-port-dev at openjdk.org>
> Cc:
> Subject: Backports to jdk11u and jdk17u
>
> Hello,
>   As we are seeing more and more adoption of RISC-V, there is a growing need for users to have access to more versions of Java available on RISC-V. Many organizations are still using Java 11 and Java 17 in production and it would be great to have RISC-V support available for them too. This would allow them to take advantage of the benefits that RISC-V offers by making their codebase more portable.
>
>
>   Taking a similar approach to AArch64 backports to JDK8u [1], we would want to create the openjdk/riscv-port-jdk11u and openjdk/riscv-port-jdk17u repositories on GitHub. Additionally, we can work with the maintainers of the JDK 11u [2] and JDK 17u [3] projects to ensure there is a possible path to getting it merged.
>
>   Some questions which I'm not sure about yet:
>   - Is there a need to backport to JDK 8u?
>   - What is the engineering cost of the divergence between JDK8u and JDK head for the backporting effort?
>
>   Looking forward to your feedback,
>
>   Thank you,
>   Ludovic
>
>   [1] https://hg.openjdk.java.net/aarch64-port/jdk8u
>   [2] https://wiki.openjdk.org/display/JDKUpdates/JDK11u#JDK11u-maintainersMaintainers
>   [3] https://wiki.openjdk.org/display/JDKUpdates/JDK+17u#JDK17u-maintainers
>
>
> </ludovic at rivosinc.com<mailto:ludovic at rivosinc.com>>
</ludovic at rivosinc.com<mailto:ludovic at rivosinc.com>>
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