[PATCH v3] MM: CMA: add a simple kernel module as the helper to test CMA

[xiyou.wangcong@gmail.com (Cong Wang)]

On 03/07/2012 12:49 PM, Barry Song wrote:
> 2012/3/7 Cong Wang<xiyou.wangcong@gmail.com>:
>> On 03/07/2012 11:14 AM, Barry Song wrote:
>>>
>>> From: Barry Song<Baohua.Song@csr.com>
>>>
>>> Any write request to /dev/cma_test will let the module to allocate memory
>>> from
>>> CMA, for example:
>>>
>>> 1st time
>>> $ echo 1024>    /dev/cma_test
>>> will require cma_test to request 1MB(1024KB)
>>> 2nd time
>>> $ echo 2048>    /dev/cma_test
>>> will require cma_test to request 2MB(2048KB)
>>>
>>> Any read request to /dev/cma_test will let the module to free the 1st
>>> valid
>>> memory from CMA, for example:
>>>
>>> 1st time
>>> $ cat /dev/cma_test
>>> will require cma_test to free the 1MB allocated in the first write request
>>> 2nd time
>>> $ cat /dev/cma_test
>>> will require cma_test to free the 2MB allocated in the second write
>>> request
>>
>>
>> Any reason why using /dev not /proc or /sys?
>
> pls note it is just a test module to verify CMA at runtime. it is not
> important either it is /dev, it is /proc or it is /sys.

Why not important? You want it to be merged, don't you?

>
> any way to make things easier, we take that way.
>

Why /dev interface is easier than /proc and /sys? Confused, actually I 
think /proc or /sys should be easier...