• Qais Yousef's avatar
    sched/fair: Detect capacity inversion · 44c7b80b
    Qais Yousef authored
    Check each performance domain to see if thermal pressure is causing its
    capacity to be lower than another performance domain.
    
    We assume that each performance domain has CPUs with the same
    capacities, which is similar to an assumption made in energy_model.c
    
    We also assume that thermal pressure impacts all CPUs in a performance
    domain equally.
    
    If there're multiple performance domains with the same capacity_orig, we
    will trigger a capacity inversion if the domain is under thermal
    pressure.
    
    The new cpu_in_capacity_inversion() should help users to know when
    information about capacity_orig are not reliable and can opt in to use
    the inverted capacity as the 'actual' capacity_orig.
    Signed-off-by: default avatarQais Yousef <qais.yousef@arm.com>
    Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
    Link: https://lore.kernel.org/r/20220804143609.515789-9-qais.yousef@arm.com
    44c7b80b
sched.h 84.6 KB