On 06/04/2013 10:44 AM, Alex Shi wrote:
> On 06/04/2013 10:33 AM, Michael Wang wrote:
>> Hi, Alex
>>
>> On 06/04/2013 09:51 AM, Alex Shi wrote:
>>> resend with a new subject.
>>
>> Forgive me but I'm a little lost on this thread...
>>
>> So we are planing to rely on instant 'cpu_load[0]' and decayed
>> 'runnable_load_avg' only, do we?
>
> cpu_load is a kind of time decay for cpu load, but after runnable load
> introduced,
> the decay functionality is a kind duplicate with it.
> So, remove them will make code simple. The idea were mentioned by Paul, Peter
> and I.
Nice, what about make a patch 9 and clean up all those stuff?
I suppose we will get more benefit :)
Regards,
Michael Wang
>
> the following is Peter's word of this affair.
>
>> Agreed, esp. the plethora of weird idx things we currently have. If we need
>> to
>> re-introduce something it would likely only be the busy case and for that we
>> can immediately link to the balance interval or so.
>
>
>>
>>
>> Regards,
>> Michael Wang
>>
>>>
>>>> Peter,
>>>>
>>>> I just tried to remove the variety rq.cpu_load, by the following patch.
>>>> Because forkexec_idx and busy_idx are all zero, after the patch system
>>>> just keep cpu_load[0]
>>>> and remove other values.
>>>> I tried the patch base 3.10-rc3 and latest tip/sched/core with benchmark
>>>> dbench,tbench,
>>>> aim7,hackbench. and oltp of sysbench. Seems performance doesn't change
>>>> clear.
>>>> So, for my tested machines, core2, NHM, SNB, with 2 or 4 CPU sockets, and
>>>> above tested
>>>> benchmark. We are fine to remove the variety cpu_load.
>>>> Don't know if there some other concerns on other scenarios.
>>>>
>>>> ---
>>>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
>>>> index 590d535..f0ca983 100644
>>>> --- a/kernel/sched/fair.c
>>>> +++ b/kernel/sched/fair.c
>>>> @@ -4626,7 +4626,7 @@ static inline void update_sd_lb_stats(struct lb_env
>>>> *env,
>>>> if (child && child->flags & SD_PREFER_SIBLING)
>>>> prefer_sibling = 1;
>>>>
>>>> - load_idx = get_sd_load_idx(env->sd, env->idle);
>>>> + load_idx = 0; //get_sd_load_idx(env->sd, env->idle);
>>>>
>>>> do {
>>>> int local_group;
>>>>
>>>>
>>>
>>>
>>
>
>
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