On 30/05/14 20:20, Vincent Guittot wrote:
On 30 May 2014 11:50, Dietmar Eggemann <dietmar.eggem...@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.guit...@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 in sd */
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().
[...]
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