Replacing a page in page_cache

[Jack David]

On Tue, Feb 28, 2012 at 2:50 AM, Mulyadi Santosa
<mulyadi.santosa at gmail.com> wrote:
> On Mon, Feb 27, 2012 at 20:41, Jack David <jd6589 at gmail.com> wrote:
>> Hi All,
>>
>> I am trying to replace a page which is already present in page_cache.
>> Is there any direct way to do so (via some kernel API)?  My experiment
>> is something like, I have a file opened and read completely in user
>> space app (just to make sure that all the file is present in page
>> cache). From kernel, I am allocating a new page, filling some data
>> into it, and want to store this data by replacing some existing page
>> from page_cache.
>
> sounds like what you want to do is like normal mmap in user space and
> then write new data into it?
>

Actually I want to share the pages (present in page cache) between two
files. I want to avoid memcopy in kernel as much as possible. I am
going through the mmap implementation in kernel but not able to
understand how it can help me in my scenario.

J