CompareAndSet fails intermittently for riscv

[wangyadong (E)]

> Let's try this:
>   https://github.com/openjdk/jdk/pull/9889

That's ok. We'll try this both on aarch64 and risc-v.

> How much you bump weakAttempts to?
We took 10 (the current default value) on our aarch64 servers and 100 on the unmatched boards, and it's often 1 failure or 2 after each tier-1 test.

-----Original Message-----
From: Aleksey Shipilev [mailto:shade at redhat.com] 
Sent: Tuesday, August 16, 2022 4:24 PM
To: wangyadong (E) <yadonn.wang at huawei.com>; Vladimir Kempik <vladimir.kempik at gmail.com>; riscv-port-dev at openjdk.org
Subject: Re: CompareAndSet fails intermittently for riscv

On 8/16/22 09:54, Aleksey Shipilev wrote:
> On 8/16/22 08:34, wangyadong (E) wrote:
>> Yes, we know about these test failures, and we've found that these 
>> failures also occur on our "powerful" aarch64 servers. I think there 
>> is some uncertainty about the test itself, and the probability of passing increased when you raise the test parameter of "weakAttempts".
> Yes, the test itself is flaky.
> 
> Unfortunately, disabling the test completely is worse option, because 
> it would miss the actual broken weak CASes.
> 
>> We now run the weak-cas tests with a high "weakAttempts" on unmatched.
> 
> How much you bump weakAttempts to?
> 
> I also think we would be better with some backoff in the loop, so that 
> we have more chance in succeeding.

Let's try this:
   https://github.com/openjdk/jdk/pull/9889

Please run it on your RISC-V machine, Vladimir?
Please run it on your AArch64 machine, Yadong?

--
Thanks,
-Aleksey