RFR: 8232782: Shenandoah: streamline post-LRB CAS barrier (aarch64)

Roman Kennke rkennke at redhat.com
Wed Jun 24 14:48:33 UTC 2020


On Wed, 2020-06-24 at 15:29 +0100, Andrew Haley wrote:
> On 24/06/2020 14:54, Nilsen, Kelvin wrote:
> > Is this ok to merge?
> 
> One thing:
> 
> Some CPUs, in particular those based on Neoverse N1, can perform very
> badly when using ldxr/stxr. For that reason, all code doing CAS
> 
> I can't see any reason why your code needs to use ldxr/stxr. Is there
> any?

As far as I know, Shenandoah's AArch64-CAS-implementation always did it
that way (don't remember why). If regular CAS is generally better, then
we should go for it.

Roman




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