Messages in this thread | | | Subject | Re: Candidate Linux ABI for Intel AMX and hypothetical new related features | From | "Enrico Weigelt, metux IT consult" <> | Date | Mon, 28 Jun 2021 12:14:02 +0200 |
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On 24.06.21 01:11, Len Brown wrote: >> x86 CPU features detection for applications (and AMX) >> <https://lore.kernel.org/linux-api/87tulo39ms.fsf@oldenburg.str.redhat.com/> > > FWIW, I didn't receive it, because you excluded > > linux-kernel@vger.kernel.org
me neither :(
Maybe just repost it to LKML ?
You mention the interface *was* designed with cpu features remaining constant over a process' lifetime. Between the line I'm reading that this might not be the case anymore.
How could that happen ? Process migration on a different CPU (or perhaps on a different host) ?
This is gonna be tricky, because this somehow needs to be synchronized with the application (even if we check the bits before calling some cpu-specific opcode, which also has some performance cost), there's still some window where the application might not yet recognize the change. So either we need some explicit migration points (where app tells, please let me finish this func first) or transparent emulation.
Damn, how could the cpu designers come up with such weird concepts in the first place ? :o
--mtx
-- --- Hinweis: unverschlüsselte E-Mails können leicht abgehört und manipuliert werden ! Für eine vertrauliche Kommunikation senden Sie bitte ihren GPG/PGP-Schlüssel zu. --- Enrico Weigelt, metux IT consult Free software and Linux embedded engineering info@metux.net -- +49-151-27565287
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