[aarch64-port-dev ] RFR: 8191955: AArch64: incorrect prefetch distance causes an internal error

[Ningsheng Jian]

Hi,

Thanks for the review! Because of the constraint func, with and
without the patch it will report an error for -1 input. But since the
constraint func is called after get_processor_features, I've updated
the patch to leave -1 to be handled by the constraint func.

http://cr.openjdk.java.net/~njian/8191955/webrev.01/

With and without patch:

$ java -XX:AllocatePrefetchDistance=-1 -version
AllocatePrefetchDistance (-1) must be between 0 and 512
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

Thanks,
Ningsheng

On 29 November 2017 at 03:50, White, Derek <Derek.White at cavium.com> wrote:
> Hi Andrew,
>
> AllocatePrefetchDistanceConstraintFunc is the bounds-checking function for AllocatePrefetchDistance. It's not possible run with -1 specified on the command line (with or without Ningsheng's patch).
>
>> java -XX:AllocatePrefetchDistance=-1 -version
> AllocatePrefetchDistance (-1) must be between 0 and 512
> Error: Could not create the Java Virtual Machine.
> Error: A fatal exception has occurred. Program will exit.
>
> - Derek
>
>> -----Original Message-----
>> From: aarch64-port-dev [mailto:aarch64-port-dev-
>> bounces at openjdk.java.net] On Behalf Of Andrew Haley
>> Sent: Tuesday, November 28, 2017 8:20 AM
>> To: Ningsheng Jian <ningsheng.jian at linaro.org>
>> Cc: hotspot compiler <hotspot-compiler-dev at openjdk.java.net>; aarch64-
>> port-dev <aarch64-port-dev at openjdk.java.net>
>> Subject: Re: [aarch64-port-dev ] RFR: 8191955: AArch64: incorrect prefetch
>> distance causes an internal error
>>
>> On 28/11/17 10:31, Ningsheng Jian wrote:
>> > OK, AllocatePrefetchDistanceConstraintFunc has constraint to make sure
>> > it should be [0, 512], which does not match document...
>>
>> OK, but this patch is about AllocatePrefetchDistance.  Does your patch work
>> with -1?
>>
>> --
>> Andrew Haley
>> Java Platform Lead Engineer
>> Red Hat UK Ltd. <https://www.redhat.com>
>> EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671