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A comment on Arvind Mithal has died. Parent comment

Re:Arvind Mithal has died by keith_analog on Thursday June 20, 2024 @01:39PM (#40741212)
There's a fairly recent study looking into the cost of raising an interrupt. TLDR: the cost on conventional systems is quite high; a significant part of the cost can be eliminated by using a custom kernel; even with a custom kernel, there remains a substantial cost.

https://par.nsf.gov/servlets/purl/10079614

To my knowledge, the remaining cost could be decreased to approximately the same cost as a branch mispredict, but getting there would require changes to the chip hardware and software stack.

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Re:Arvind Mithal has died by Dylan16807 on Thursday June 20, 2024 @04:24PM (#40742960)
> To my knowledge, the remaining cost could be decreased to approximately the same cost as a branch mispredict, but getting there would require changes to the chip hardware and software stack.

Do it even need to be a misprediction?

If you are completely focused on latency then flushing everything else makes sense. But I would think that if you continue execution for now and put a branch instruction into the queue you'd reduce the cost per interrupt even further.

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