On 05/23/2013 04:34 PM, Lukasz Majewski wrote: > Now explicit casting is done when power usage variable (putil) is calculated > > Signed-off-by: Lukasz Majewski <[email protected]> > Signed-off-by: Kyungmin Park <[email protected]> > --- > This patch was developed on top of the following Alex's repository: > https://github.com/alexshi/power-scheduling/commits/power-scheduling > --- > kernel/sched/fair.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) >
Thanks for catch this issue. seems use div_u64 is better, and there are 2 same bugs. so, could I rewrite the patch like following? --- >From 9f72c25607351981898d99822f5a66e0ca67a3da Mon Sep 17 00:00:00 2001 From: Alex Shi <[email protected]> Date: Wed, 29 May 2013 11:09:39 +0800 Subject: [PATCH 1/2] sched: fix cast on power utilization calculation and use div_u64 Now explicit casting is done when power usage variable (putil) is calculated. div_u64 is optimized on u32. Signed-off-by: Lukasz Majewski <[email protected]> Signed-off-by: Kyungmin Park <[email protected]> Signed-off-by: Alex Shi <[email protected]> --- kernel/sched/fair.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 09ae48a..3a4917c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1504,8 +1504,8 @@ static inline void update_rq_runnable_avg(struct rq *rq, int runnable) __update_tg_runnable_avg(&rq->avg, &rq->cfs); period = rq->avg.runnable_avg_period ? rq->avg.runnable_avg_period : 1; - rq->util = (u64)(rq->avg.runnable_avg_sum << SCHED_POWER_SHIFT) - / period; + rq->util = div_u64(((u64)rq->avg.runnable_avg_sum << SCHED_POWER_SHIFT), + period); } /* Add the load generated by se into cfs_rq's child load-average */ @@ -3407,8 +3407,8 @@ static int is_sd_full(struct sched_domain *sd, /* p maybe a new forked task */ putil = FULL_UTIL; else - putil = (u64)(p->se.avg.runnable_avg_sum << SCHED_POWER_SHIFT) - / (p->se.avg.runnable_avg_period + 1); + putil = div_u64(((u64)p->se.avg.runnable_avg_sum << SCHED_POWER_SHIFT), + p->se.avg.runnable_avg_period + 1); /* Try to collect the domain's utilization */ group = sd->groups; @@ -3463,9 +3463,11 @@ find_leader_cpu(struct sched_group *group, struct task_struct *p, int this_cpu, int vacancy, min_vacancy = INT_MAX; int leader_cpu = -1; int i; + /* percentage of the task's util */ - unsigned putil = (u64)(p->se.avg.runnable_avg_sum << SCHED_POWER_SHIFT) - / (p->se.avg.runnable_avg_period + 1); + unsigned putil; + putil = div_u64(((u64)p->se.avg.runnable_avg_sum << SCHED_POWER_SHIFT), + p->se.avg.runnable_avg_period + 1); /* bias toward local cpu */ if (cpumask_test_cpu(this_cpu, tsk_cpus_allowed(p)) && -- 1.7.12 -- Thanks Alex -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
