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A comment on Intel Discloses Lakefield CPUs Specifications. Parent comment

Re:Intel Discloses Lakefield CPUs Specifications by fluffy87 on Wednesday June 10, 2020 @02:05PM (#23480166)
Binaries need to target a minimum subset, but can use run time feature detection to query differences.

If a binary does that, the OS can just not migrate that binary across cores.

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Re:Intel Discloses Lakefield CPUs Specifications by loeg on Wednesday June 10, 2020 @02:13PM (#23480269)
How would the OS know?

The only mechanism I can come up with is to detect illegal instruction traps on small cores, then flag the thread as big-core-only and re-start the execution at the bad instruction. That's not ideal but maybe workable.

(If it traps on the big core, too, it's just a bad instruction and SIGILL is raised to userspace like usual.)

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