On 1 June 2014 13:33, Dietmar Eggemann dietmar.eggemann@arm.com wrote:
On 30/05/14 20:20, Vincent Guittot wrote:
On 30 May 2014 11:50, Dietmar Eggemann dietmar.eggemann@arm.com wrote:
On 23/05/14 16:53, Vincent Guittot wrote:
Monitor the activity level of each group of each sched_domain level. The activity is the amount of cpu_power that is currently used on a CPU or group of CPUs. We use the runnable_avg_sum and _period to evaluate this activity level. In the special use case where the CPU is fully loaded by more than 1 task, the activity level is set above the cpu_power in order to reflect the overload of the CPU
Signed-off-by: Vincent Guittot vincent.guittot@linaro.org
[...]
/*
- select_task_rq_fair: Select target runqueue for the waking task in
domains
- that have the 'sd_flag' flag set. In practice, this is
SD_BALANCE_WAKE, @@ -5518,6 +5535,7 @@ struct sg_lb_stats { unsigned long sum_weighted_load; /* Weighted load of group's tasks */ unsigned long load_per_task; unsigned long group_power;
unsigned long group_activity; /* Total activity of the group */ unsigned int sum_nr_running; /* Nr tasks running in the group */ unsigned int group_capacity; unsigned int idle_cpus;@@ -5538,6 +5556,7 @@ struct sd_lb_stats { struct sched_group *busiest; /* Busiest group in this sd */ struct sched_group *local; /* Local group in this sd */ unsigned long total_load; /* Total load of all groups in sd */
unsigned long total_activity; /* Total activity of all groups insd */ unsigned long total_pwr; /* Total power of all groups in sd */ unsigned long avg_load; /* Average load across all groups in sd */
@@ -5557,6 +5576,7 @@ static inline void init_sd_lb_stats(struct sd_lb_stats *sds) .busiest = NULL, .local = NULL, .total_load = 0UL,
.total_activity = 0UL,AFAICS, total_activity is not used right now. Do you intend to use it to calculate something like avg_activity later (like total_load/avg_load)?
this patch only creates group_activity and total_activity.The use of these statistics appears on the next patches. I have not planned to compute such avg_activity for the moment mainly because i have need it yet.
Do you have in mind any use of such avg_activity ?
No, not really but I still don't see (taken all your patches) where sds->total_activity is used.
$ find . -name "*.[ch]" | xargs grep total_activity ./kernel/sched/fair.c: unsigned long total_activity; /* Total activity of all groups in sd */ ./kernel/sched/fair.c: .total_activity = 0UL, ./kernel/sched/fair.c: sds->total_activity += sgs->group_activity;
OOTH, sgs->group_activity is used to set sgs->group_capacity which is then used in if conditions in update_sd_pick_busiest(), update_sd_lb_stats() and find_busiest_group().
Sorry, i misread you 1st email and haven't understood that you were specifically speaking about total_activity. When i created the activity statistic, i have added both sg and sd fields but i finally only use the sg one. If i don't need the sd field after updating my patches, i will remove it
Thanks Vincent
[...]