Re: [PATCH]cgroup: __cpuset_node_allowed return bool

From: yuankuiz@codeaurora.org
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
Subject: Re: [PATCH]cgroup: __cpuset_node_allowed return bool
Date: Mon, 26 Mar 2018 22:37:31 +0800	[thread overview]
Message-ID: <ea271bc26e293c232c6ea7772607c7fc@codeaurora.org> (raw)
In-Reply-To: <20180326142527.GJ2149215@devbig577.frc2.facebook.com>

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.
> 
>>  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.