Messages in this thread Patch in this message | | | Subject | Re: volanoMark regression with kernel 2.6.26-rc1 | From | Peter Zijlstra <> | Date | Wed, 14 May 2008 17:12:47 +0200 |
| |
> +#define GROUP_SCALE (2*1024) > + > static inline void inc_cpu_load(struct rq *rq, unsigned long load) > { > + load *= GROUP_SCALE; > update_load_add(&rq->load, load); > } > > static inline void dec_cpu_load(struct rq *rq, unsigned long load) > { > + load *= GROUP_SCALE; > update_load_sub(&rq->load, load); > }
Yeah, this bit makes a huge difference; I do that by:
mkdir /cgroup/foo for i in `cat /cgroup/tasks`; do echo $i > /cgroup/foo/tasks; done echo $((1024*1024)) > /cgroup/foo/cpu.shares
I'm still pulling my hairs out on why this makes a difference though - I eliminated all direct assumption on SCHED_LOAD_SCALE(_FUZZ) with an average of the weight per task. - but all that doesn't help (much)
A few other things I found that make a significant difference:
+static void update_aggregate(int cpu, struct sched_domain *sd) +{ + aggregate_walk_tree(aggregate_get_down, aggregate_get_nop, cpu, sd); +}
@@ -3224,6 +3189,8 @@ static int move_tasks(struct rq *this_rq, int this_cpu, st ruct rq *busiest, unsigned long total_load_moved = 0; int this_best_prio = this_rq->curr->prio;
+ update_aggregate(this_cpu, sd); + do { total_load_moved += class->load_balance(this_rq, this_cpu, busiest,
and
@@ -1169,7 +1168,10 @@ static unsigned long wakeup_gran(struct sched_entity *se) * More easily preempt - nice tasks, while not making it harder for * + nice tasks. */ - gran = calc_delta_asym(sysctl_sched_wakeup_granularity, se); + if (sched_feat(ASYM_GRAN)) + gran = calc_delta_asym(sysctl_sched_wakeup_granularity, se); + else + gran = calc_delta_fair(sysctl_sched_wakeup_granularity, se); return gran; }
the asym logic is wrong wrt shares - it should look at tg->weight
| |