• Vincent Guittot's avatar
    sched/core: Use PELT for scale_rt_capacity() · 523e979d
    Vincent Guittot authored
    The utilization of the CPU by RT, DL and IRQs are now tracked with
    PELT so we can use these metrics instead of rt_avg to evaluate the remaining
    capacity available for CFS class.
    
    scale_rt_capacity() behavior has been changed and now returns the remaining
    capacity available for CFS instead of a scaling factor because RT, DL and
    IRQ provide now absolute utilization value.
    
    The same formula as schedutil is used:
    
      IRQ util_avg + (1 - IRQ util_avg / max capacity ) * /Sum rq util_avg
    
    but the implementation is different because it doesn't return the same value
    and doesn't benefit of the same optimization.
    Signed-off-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
    Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Morten.Rasmussen@arm.com
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: claudio@evidence.eu.com
    Cc: daniel.lezcano@linaro.org
    Cc: dietmar.eggemann@arm.com
    Cc: joel@joelfernandes.org
    Cc: juri.lelli@redhat.com
    Cc: luca.abeni@santannapisa.it
    Cc: patrick.bellasi@arm.com
    Cc: quentin.perret@arm.com
    Cc: rjw@rjwysocki.net
    Cc: valentin.schneider@arm.com
    Cc: viresh.kumar@linaro.org
    Link: http://lkml.kernel.org/r/1530200714-4504-10-git-send-email-vincent.guittot@linaro.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    523e979d
fair.c 267 KB