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

[Barry Song]

2012/3/7 Cong Wang <xiyou.wangcong at gmail.com>:
> On 03/07/2012 12:49 PM, Barry Song wrote:
>>
>> 2012/3/7 Cong Wang<xiyou.wangcong at gmail.com>:
>>>
>>> On 03/07/2012 11:14 AM, Barry Song wrote:
>>>>
>>>>
>>>> From: Barry Song<Baohua.Song at 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...

if you think so, pls do that and send v4 with your s-o-b.

-barry