Re: [PATCH 3/3] KVM: MMU: Consolidate common code in mmu_free_roots()

[Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>]

On 05/13/2013 07:24 PM, Gleb Natapov wrote:
> On Fri, May 10, 2013 at 09:43:50AM +0800, Xiao Guangrong wrote:
>> On 05/10/2013 09:05 AM, Takuya Yoshikawa wrote:
>>> On Thu, 09 May 2013 18:11:31 +0800
>>> Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> wrote:
>>>
>>>> On 05/09/2013 02:46 PM, Takuya Yoshikawa wrote:
>>>>> By making the last three statements common to both if/else cases, the
>>>>> symmetry between the locking and unlocking becomes clearer. One note
>>>>> here is that VCPU's root_hpa does not need to be protected by mmu_lock.
>>>>>
>>>>> Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
>>>>> ---
>>>>>  arch/x86/kvm/mmu.c |   39 +++++++++++++++++++--------------------
>>>>>  1 files changed, 19 insertions(+), 20 deletions(-)
>>>>
>>>> DO NOT think it makes any thing better.
>>>>
>>>
>>> Why do we need to do the same thing differently in two paths?
>>
>> They are different cases, one is the long mode, anther is PAE mode,
>> return from one case and continue to handle the anther case is common
>> used, and it can reduce the indentation and easily follow the code.
>>
> I agree that this is mostly code style issue and with Takuya patch the
> indentation is dipper. Also the structure of mmu_free_roots() resembles
> mmu_alloc_shadow_roots() currently. The latter has the same if(){return}
> pattern. I also agree with Takuya that locking symmetry can be improved.
> What about something like this (untested):

It is good to me! ;)