From mboxrd@z Thu Jan  1 00:00:00 1970
From: 21cnbao@gmail.com (Barry Song)
Date: Wed, 7 Mar 2012 12:49:21 +0800
Subject: [PATCH v3] MM: CMA: add a simple kernel module as the helper to
 test CMA
In-Reply-To: <4F56E0AC.8070501@gmail.com>
References: <1331090098-25097-1-git-send-email-Barry.Song@csr.com>
 <4F56E0AC.8070501@gmail.com>
Message-ID: <CAGsJ_4x4CwD+WAE9d+Xob_tfwqmE6SdBdBd5EbC64XBi4Uzvgg@mail.gmail.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

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.

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

-barry