On 01/23/2014 05:54 PM, Peter Zijlstra wrote:
> On Thu, Jan 23, 2014 at 02:49:25PM +0800, Alex Shi wrote:
>> On 01/23/2014 02:10 AM, Jason Low wrote:
>>>>>>> P64(avg_idle);
>>>>>>> + P64(max_idle_balance_cost);
>>>>>>> #endif
>>>>>>> P(ttwu_count);
>>>>>
>>>>> Not also the per-sd value in sd_alloc_ctl_domain_table() ?
>>> Yeah, tracking the sd->max_newidle_lb_cost can also be useful.
>>>
>>>
>>
>> Thanks for suggestion!
>>
>> I thought the sd->max_newidle_lb_cost keep changing. But yes, it's
>> still meaningful.
>> BTW, in the pandaboard ES, sd balance cost is about 1~2ms.
>
> That's an insane amount of time for only 2 cpus.
maybe, :(
but it is the data.
$ cat /proc/sys/kernel/sched_domain/cpu0/domain0/max_newidle_lb_cost
1873393
>
>> ---
>>
[...]
>> sd_alloc_ctl_domain_table(struct sched_domain *sd)
>> {
>> - struct ctl_table *table = sd_alloc_ctl_entry(8);
>> + struct ctl_table *table = sd_alloc_ctl_entry(9);
>
> tip/master has 13 there, not 8.
>
Sorry about this. updated on tip/master.
-----
>From c49ae4749ffa2d1f95bd0d8b3c8e6fbce8864f04 Mon Sep 17 00:00:00 2001
From: Alex Shi <alex....@linaro.org>
Date: Thu, 23 Jan 2014 18:39:54 +0800
Subject: [PATCH] sched: add statistic for newidle load balance cost
Tracking rq->max_idle_balance_cost and sd->max_newidle_lb_cost.
It's useful to know these values in debug mode.
Signed-off-by: Alex Shi <alex....@linaro.org>
---
kernel/sched/core.c | 9 ++++++---
kernel/sched/debug.c | 1 +
2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 36c951b..4740456 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4815,7 +4815,7 @@ set_table_entry(struct ctl_table *entry,
static struct ctl_table *
sd_alloc_ctl_domain_table(struct sched_domain *sd)
{
- struct ctl_table *table = sd_alloc_ctl_entry(13);
+ struct ctl_table *table = sd_alloc_ctl_entry(14);
if (table == NULL)
return NULL;
@@ -4843,9 +4843,12 @@ sd_alloc_ctl_domain_table(struct sched_domain *sd)
sizeof(int), 0644, proc_dointvec_minmax, false);
set_table_entry(&table[10], "flags", &sd->flags,
sizeof(int), 0644, proc_dointvec_minmax, false);
- set_table_entry(&table[11], "name", sd->name,
+ set_table_entry(&table[11], "max_newidle_lb_cost",
+ &sd->max_newidle_lb_cost,
+ sizeof(long), 0644, proc_doulongvec_minmax, false);
+ set_table_entry(&table[12], "name", sd->name,
CORENAME_MAX_SIZE, 0444, proc_dostring, false);
- /* &table[12] is terminator */
+ /* &table[13] is terminator */
return table;
}
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index dd52e7f..7f17a38 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -321,6 +321,7 @@ do {
\
P(sched_goidle);
#ifdef CONFIG_SMP
P64(avg_idle);
+ P64(max_idle_balance_cost);
#endif
P(ttwu_count);
--
1.8.1.2
--
Thanks
Alex
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