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From: yuankuiz@codeaurora.org
Subject: Re: [PATCH]cgroup: __cpuset_node_allowed return bool
Date: Mon, 26 Mar 2018 22:41:59 +0800
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To: Tejun Heo <tj@kernel.org>
Cc: cgroups@vger.kernel.org, lizefan@huawei.com, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, pkondeti@codeaurora.org, cgroups-owner@vger.kernel.org

Hi Tejun,

     Additionally,

On 2018-03-26 10:37 PM, yuankuiz@codeaurora.org wrote:
> Hi Tejun,
> 
>     inline.
> 
> On 2018-03-26 10:25 PM, Tejun Heo wrote:
>> On Mon, Mar 26, 2018 at 10:20:43PM +0800, yuankuiz@codeaurora.org 
>> wrote:
>>>  1) return int type variable in bool function:
>>>  bool enabled()
>>>  {
>>>  	int ret = 1;
>>>  	return ret;
>>>  }
>> ...
>>>  2)
>>>  bool enabled()
>>>  {
>>>  	bool ret = 1;
>>>  	return ret;
>>>  }
>> ...
>>>  so the #1) style function can generate significant instructions
>>> than the #2).
>> 
>> That is a problem for the compiler, not the code.
[ZJ] Actually, it should be bool but not int. Without any optimization 
by compiler, it is the best if it is the same as returned.

>> 
>>>  While, this is happened only when "-On" is not used with *-gcc
>>> together. Though, it is oftern there, it is best to provide this
>>> with decoupling of which option is used for optimization.
>> 
>> We don't want to dictate minute coding styles to avoid things which
>> are trivially optimized by compilers.
> [ZJ] Optimized by compiler is observed only. Such as it is not so big
> difference in x86-arch.
> 
>> 
>> Thanks.
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     Thanks,
BR//Zhao