Evolution of the x86 context switch in Linux (2018)

The exercise: Trace the context switch through the Linux kernel from the earliest (0.01) to the most recent LTS release (4.14.67) — with special emphasis on the first and last versions. Hardware context switch

The jump address in __tmp identifies a TSS descriptor within the GDT. If the last task did not restore the coprocessor, jump to the end of the context switch. This assembly block has no outputs and the first input (%0) is a memory location of the first 4 bytes of the far pointer to the TSS descriptor in the GDT.

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