RFR: 8277137: Set OnSpinWaitInst/OnSpinWaitInstCount defaults to "isb"/1 for Arm Neoverse N1 [v3]

[Evgeny Astigeevich]

On Wed, 17 Nov 2021 16:32:45 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> Evgeny Astigeevich has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Set defaults for OnSpinWaitInst/OnSpinWaitInstCount independently
>
> Hi,
> 
>> > Did we establish that this is the right default for Neoverse N1?
>> 
>> This is based on:
>> 
>>     * MySql: https://bugs.mysql.com/bug.php?id=100664
>> 
>>     * MongoDB: https://jira.mongodb.org/browse/WT-6872
>> 
>>     * Netty: [Use cpu_relax() implementation for aarch64 netty/netty#11677](https://github.com/netty/netty/pull/11677)
>> 
>>     * Customers' benchmarks and workloads.
>> 
>>     * Experiments with two and three `ISB` instructions.
> 
> OK, I'll buy that.

@theRealAph Thank you.

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PR: https://git.openjdk.java.net/jdk/pull/6415