Messages in this thread | | | Date | Wed, 19 Feb 2020 14:02:17 +0000 | From | Mel Gorman <> | Subject | Re: [PATCH v3 4/5] sched/pelt: Add a new runnable average signal |
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On Wed, Feb 19, 2020 at 01:55:13PM +0100, Vincent Guittot wrote: > Now that runnable_load_avg has been removed, we can replace it by a new > signal that will highlight the runnable pressure on a cfs_rq. This signal > track the waiting time of tasks on rq and can help to better define the > state of rqs. > > At now, only util_avg is used to define the state of a rq: > A rq with more that around 80% of utilization and more than 1 tasks is > considered as overloaded. > > But the util_avg signal of a rq can become temporaly low after that a task > migrated onto another rq which can bias the classification of the rq. > > When tasks compete for the same rq, their runnable average signal will be > higher than util_avg as it will include the waiting time and we can use > this signal to better classify cfs_rqs. > > The new runnable_avg will track the runnable time of a task which simply > adds the waiting time to the running time. The runnable _avg of cfs_rq > will be the /Sum of se's runnable_avg and the runnable_avg of group entity > will follow the one of the rq similarly to util_avg. > > Tested-by: Valentin Schneider <valentin.schneider@arm.com> > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Thanks.
Picked up and included in "Reconcile NUMA balancing decisions with the load balancer v4". The only change I made to your patches was move the reintroduction of cpu_runnable to the patch that requires it to avoid a build warning.
-- Mel Gorman SUSE Labs
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