Re: [PATCH v6 02/10] cpuidle: rename ARCH_HAS_CPU_RELAX to ARCH_HAS_OPTIMIZED_POLL

From: Christoph Lameter (Ampere)
Date: Mon Aug 05 2024 - 21:04:05 EST


On Fri, 26 Jul 2024, Ankur Arora wrote:

However, recent changes in poll_idle() mean that a higher level
primitive -- smp_cond_load_relaxed() is used for polling. This would
in-turn use cpu_relax() or an architecture specific implementation.


Maybe explain here that smp_cond_load_relaxed will potentially wait for important events such as a cacheline changing. Thereby making the busy poll unnecessary and optimizing power use.