Subject: Re: [PATCH 02/10] KVM: x86: MMU: Add helper function to clear a bit
 in unsync child bitmap
To: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>, pbonzini@redhat.com
References: <20151112204849.ba920599a8426d7196a0df73@lab.ntt.co.jp>
 <20151112205019.611e8216adebb465b689876e@lab.ntt.co.jp>
 <564BE628.1050705@linux.intel.com> <564D1EF7.4000707@lab.ntt.co.jp>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
From: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Message-ID: <564D3816.8080609@linux.intel.com>
Date: Thu, 19 Nov 2015 10:46:46 +0800
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On 11/19/2015 08:59 AM, Takuya Yoshikawa wrote:
> On 2015/11/18 11:44, Xiao Guangrong wrote:
>
>> On 11/12/2015 07:50 PM, Takuya Yoshikawa wrote:
>>> +            if (!ret) {
>>> +                clear_unsync_child_bit(sp, i);
>>> +                continue;
>>> +            } else if (ret > 0) {
>>>                   nr_unsync_leaf += ret;
>>
>> Just a single line here, braces are unnecessary.
>>
>>> -            else
>>> +            } else
>>>                   return ret;
>
> I know we can eliminate the braces, but that does not mean
> we should do so: there seems to be no consensus about this
> style issue and checkpatch accepts both ways.
>
> Actually, some people prefer to put braces when one of the
> if/else-if/else cases has multiple lines.  You can see
> some examples in kernel/sched/core.c: see hrtick_start(),
> sched_fork(), free_sched_domain().
>
> In our case, I thought putting braces would align the else-if
> and else and make the code look a bit nicer, but I know this
> may be just a matter of personal feeling.
>
> In short, unless the maintainer, Paolo for this file, has any
> preference, both ways will be accepted.

The reason why i pointed this out is that it is the style documented
in Documentation/CodingStyle:
| Do not unnecessarily use braces where a single statement will do.
|
|        if (condition)
|                action();
|

Actually, Ingo Molnar hated this braces-style too much and blamed
many developers who used this style (include me, that why i was
nervous to see this style :( ).

If this style is commonly accepted now, it is worth making a patch
to update Documentation/CodingStyle.

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