On Sun, Nov 23, 2008 at 2:23 AM, Rik van Riel <[EMAIL PROTECTED]> wrote:
> Peter Teoh wrote: > >> when a process mmap() a section of a file into its own process memory, >> the process memory will maintain a copy of the data of that section of >> the file. >> > > No, it does not maintain a copy. > > It mmaps the page cache pages into its own address space. > According to your explanation, the flow is physical file(on disk)-->Page Cache(on memory, but in kernel space)-->Process Memory(on memory, but in user space). Is it? I am not sure.... > > > so...does there exists duplicated buffering? (one in kernel - >> pagecache, and one in userspace - for mmap() content of the file in >> process memory) >> > > No, there is no such double buffering. But what is the difference? Why linux do it? > > > -- > All rights reversed. > > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to [EMAIL PROTECTED] > Please read the FAQ at http://kernelnewbies.org/FAQ > > -- National Research Center for Intelligent Computing Systems Institute of Computing Technology, Chinese Academy of Sciences
