Re: [PATCH v2] mm: cma: support sysfs

John Hubbard
2021-02-09T05:19:55Z

On 2/8/21 8:19 PM, Minchan Kim wrote:
> On Mon, Feb 08, 2021 at 05:57:17PM -0800, John Hubbard wrote:
>> On 2/8/21 3:36 PM, Minchan Kim wrote:
>> ...
>>>>> char name[CMA_MAX_NAME];
>>>>> +#ifdef CONFIG_CMA_SYSFS
>>>>> + struct cma_stat *stat;
>>>>
>>>> This should not be a pointer. By making it a pointer, you've added a bunch of pointless
>>>> extra code to the implementation.
>>>
>>> Originally, I went with the object lifetime with struct cma as you
>>> suggested to make code simple. However, Greg KH wanted to have
>>> release for kobj_type since it is consistent with other kboject
>>> handling.
>>
>> Are you talking about the kobj in your new struct cma_stat? That seems
>> like circular logic if so. I'm guessing Greg just wanted kobj methods
>> to be used *if* you are dealing with kobjects. That's a narrower point.
>>
>> I can't imagine that he would have insisted on having additional
>> allocations just so that kobj freeing methods could be used. :)
>
> I have no objection if Greg agree static kobject is okay in this
> case. Greg?
>

What I meant is, no kobject at all in the struct cma_stat member
variable. The lifetime of the cma_stat member is the same as the
containing struct, so no point in putting a kobject into it.

thanks,
--
John Hubbard
NVIDIA