lkml.org 
[lkml]   [2018]   [Dec]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH 3/3] sched/fair: fix unnecessary increase of balance interval
On Tue, Aug 07, 2018 at 05:56:27PM +0200, Vincent Guittot wrote:
> +static inline bool
> +asym_active_balance(enum cpu_idle_type idle, unsigned int flags, int dst, int src)
> {
> + if (idle != CPU_NOT_IDLE) {
>
> /*
> * ASYM_PACKING needs to force migrate tasks from busy but
> * lower priority CPUs in order to pack all tasks in the
> * highest priority CPUs.
> */
> + if ((flags & SD_ASYM_PACKING) &&
> + sched_asym_prefer(dst, src))
> + return true;
> }
>
> + return false;
> +}
> +
> +static int need_active_balance(struct lb_env *env)
> +{
> + struct sched_domain *sd = env->sd;
> +
> +
> + if (asym_active_balance(env->idle, sd->flags, env->dst_cpu, env->src_cpu))
> + return 1;
> +
> /*
> * The dst_cpu is idle and the src_cpu CPU has only 1 CFS task.
> * It's worth migrating the task if the src_cpu's capacity is reduced
> @@ -8650,7 +8660,8 @@ static int load_balance(int this_cpu, struct rq *this_rq,
> } else
> sd->nr_balance_failed = 0;
>
> + if (likely(!active_balance) ||
> + asym_active_balance(env.idle, sd->flags, env.dst_cpu, env.src_cpu)) {

Perhaps like the below?

--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -8857,21 +8857,24 @@ static struct rq *find_busiest_queue(str
*/
#define MAX_PINNED_INTERVAL 512

+static inline bool
+asym_active_balance(struct lb_env *env)
+{
+ /*
+ * ASYM_PACKING needs to force migrate tasks from busy but
+ * lower priority CPUs in order to pack all tasks in the
+ * highest priority CPUs.
+ */
+ return env->idle != CPU_NOT_IDLE && (env->sd->flags & SD_ASYM_PACKING) &&
+ sched_asym_prefer(env->dst_cpu, env->src_cpu);
+}
+
static int need_active_balance(struct lb_env *env)
{
struct sched_domain *sd = env->sd;

- if (env->idle != CPU_NOT_IDLE) {
-
- /*
- * ASYM_PACKING needs to force migrate tasks from busy but
- * lower priority CPUs in order to pack all tasks in the
- * highest priority CPUs.
- */
- if ((sd->flags & SD_ASYM_PACKING) &&
- sched_asym_prefer(env->dst_cpu, env->src_cpu))
- return 1;
- }
+ if (asym_active_balance(env))
+ return 1;

/*
* The dst_cpu is idle and the src_cpu CPU has only 1 CFS task.
@@ -9150,7 +9153,7 @@ static int load_balance(int this_cpu, st
} else
sd->nr_balance_failed = 0;

- if (likely(!active_balance)) {
+ if (likely(!active_balance) || asym_active_balance(&env)) {
/* We were unbalanced, so reset the balancing interval */
sd->balance_interval = sd->min_interval;
} else {
\
 
 \ /
  Last update: 2018-12-13 14:52    [W:0.112 / U:1.504 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site