Messages in this thread | | | From | Keith Cancel <> | Date | Fri, 5 Nov 2021 23:26:39 +0000 | Subject | Re: Intel Alder Lake Question (Scheduler) |
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Hello Gayatri,
So I was searching through the mailing list looking at various patches. I don't see any for alder lake regarding what I was mentioning. Is there something I am overlooking? I did see you were on multiple email chains for adding alder so maybe you have a better idea.
Thanks, Keith Cancel
On Fri, Nov 5, 2021 at 7:51 AM Keith Cancel <admin@keith.pro> wrote: > > Hello, > > So Alder lake was supposed to have AVX-512 disabled/fused off. So it > looks like that was not the case. For example see this news article: > https://www.anandtech.com/show/17047/the-intel-12th-gen-core-i912900k-review-hybrid-performance-brings-hybrid-complexity/2 > > This issue I noticed it seems to be the possibility that a bios could > allow someone to enable both AVX-512 and and E-Cores (efficiency > cores). How on earth would the scheduler handle this? I could imagine > the scheduler switching a process/thread using AVX-512 to an > efficiency core. Now suddenly the core the thread/process is running > no longer has AVX-512 instructions... This sounds like a headache. > > I suppose the kernel could handle the trap and then from on only > schedule such a process on performance cores. This issue I see here > though is userland process could then intentionally trigger such a > trap to then only be scheduled on a performance core. Even if it does > not use AVX-512 otherwise. > > Thanks, > Keith Cancel
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