Re: [patch v6 6/8] sched: compute runnable load avg in cpu_load andcpu_avg_load_per_task

From: Peter Zijlstra
Date: Mon May 13 2013 - 10:09:32 EST


On Fri, May 10, 2013 at 11:17:27PM +0800, Alex Shi wrote:
> They are the base values in load balance, update them with rq runnable
> load average, then the load balance will consider runnable load avg
> naturally.
>
> We also try to include the blocked_load_avg as cpu load in balancing,
> but that cause kbuild/aim7/oltp benchmark performance drop.
>
> Signed-off-by: Alex Shi <alex.shi@xxxxxxxxx>
> ---
> kernel/sched/core.c | 16 ++++++++++++++--
> kernel/sched/fair.c | 5 +++--
> 2 files changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index f1f9641..8ab37c3 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -2528,9 +2528,14 @@ static void __update_cpu_load(struct rq *this_rq, unsigned long this_load,
> void update_idle_cpu_load(struct rq *this_rq)
> {
> unsigned long curr_jiffies = ACCESS_ONCE(jiffies);
> - unsigned long load = this_rq->load.weight;
> + unsigned long load;
> unsigned long pending_updates;
>
> +#ifdef CONFIG_SMP
> + load = this_rq->cfs.runnable_load_avg;
> +#else
> + load = this_rq->load.weight;
> +#endif
> /*
> * bail if there's load or we're actually up-to-date.
> */
> @@ -2574,11 +2579,18 @@ void update_cpu_load_nohz(void)
> */
> static void update_cpu_load_active(struct rq *this_rq)
> {
> + unsigned long load;
> +
> +#ifdef CONFIG_SMP
> + load = this_rq->cfs.runnable_load_avg;
> +#else
> + load = this_rq->load.weight;
> +#endif
> /*
> * See the mess around update_idle_cpu_load() / update_cpu_load_nohz().

This just smells like you want a helper function... :-)

Also it doesn't apply anymore due to Paul Gortemaker moving some of this
stuff about.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/