add option to use a busy waiting within the idle loop#1243
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mkroening merged 5 commits intohermit-os:mainfrom Jun 6, 2024
Merged
add option to use a busy waiting within the idle loop#1243mkroening merged 5 commits intohermit-os:mainfrom
mkroening merged 5 commits intohermit-os:mainfrom
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Looks good to me aside from one nit. I'll run CI on the in-between commits too, to make sure there's no breakage.
- avoid using the halt instruction - CPU waits until another CPU change the ready queue - doesn't require wakeup IPIs
=> using busy waiting loop
…ate` Signed-off-by: Martin Kröning <martin.kroening@eonerc.rwth-aachen.de>
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Instead of the
hltinstruction, the idle loop use thepauseinstruction. => lower latency to wake up the core, but higher energy consumption.In addition, this PR support
monitor/mwaitinstructions. In this, the kernel hasn't to send an IPI to wakeup a core. The second optimization is that the kernels sends only an IPI, if the core is halted.