2 May
2025
2 May
'25
11:22 a.m.
On Wed, Apr 30, 2025 at 11:07:35AM -0700, Dave Hansen wrote:
Both AMD and Intel have hardware to do it. ARM CPUs do it too, I think. You can go buy the Intel hardware off the shelf today.
To be fair, the Intel RAR thing is pretty horrific :-( Definitely sub-par compared to the AMD and ARM things.
Furthermore, the paper states it is a uarch feature for SPR with no guarantee future uarchs will get it (and to be fair, I'd prefer it if they didn't).
Furthermore, I suspect it will actually be slower than IPIs for anything with more than 64 logical CPUs due to reduced parallelism.