27 Mar
2015
27 Mar
'15
3:59 p.m.
On 27 March 2015 at 15:52, Xunlei Pang pang.xunlei@linaro.org wrote:
Hi Vincent,
On 27 February 2015 at 23:54, Vincent Guittot vincent.guittot@linaro.org wrote:
/** @@ -6432,18 +6435,19 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
/* * In case the child domain prefers tasks go to siblings
* first, lower the sg capacity factor to one so that we'll try
* first, lower the sg capacity so that we'll try * and move all the excess tasks away. We lower the capacity * of a group only if the local group has the capacity to fit
* these excess tasks, i.e. nr_running < group_capacity_factor. The* extra check prevents the case where you always pull from the* heaviest group when it is already under-utilized (possible* with a large weight task outweighs the tasks on the system).
* these excess tasks. The extra check prevents the case where* you always pull from the heaviest group when it is already* under-utilized (possible with a large weight task outweighs* the tasks on the system). */ if (prefer_sibling && sds->local &&
sds->local_stat.group_has_free_capacity) {sgs->group_capacity_factor = min(sgs->group_capacity_factor, 1U);sgs->group_type = group_classify(sg, sgs);
group_has_capacity(env, &sds->local_stat) &&(sgs->sum_nr_running > 1)) {sgs->group_no_capacity = 1;sgs->group_type = group_overloaded; }For SD_PREFER_SIBLING, if local has 1 task and group_has_capacity() returns true(but not overloaded) for it, and assume sgs group has 2 tasks, should we still mark this group overloaded?
yes, the load balance will then choose if it's worth pulling it or not depending of the load of each groups
-Xunlei