RFR: 8255799: AArch64: CPU_A53MAC feature may be set incorrectly

[Andrew Haley]

On 05/11/2020 01:52, Nick Gasson wrote:
> On Wed, 4 Nov 2020 16:46:36 GMT, Andrew Dinn <adinn at openjdk.org> wrote:
> 
>>
>> At present reading /proc/cpuinfo that is the only reliable way I know of to identify whether dcpop is a supported feature (used to force persistence of data to memory). That is needed to support use of NVRAM-backed MappedByteBuffers.
> 
> I think that comes from `getauxval() & HWCAP_DCPOP`?

If there's anything we need from /proc/cpuinfo in order to run Java, we
really should be raising a bug with the kernel people.

And besides, what happens if you try to use dcpop and it's not supported?
If you get SIGILL, then we're done. We don't have to ask permission if we
can try it.

-- 
Andrew Haley  (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
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