> > mapped data. Will both these pages ( the page that holds > > the buffer_head > > structure and buffer page that contains the actual data) > > mapped to the > > process OR only the page with the buffer_head is mapped > > to the process ? > > The buffer head is never mapped into user address space. > It is a kernel data structure and doesn't have to be > accessed from userspace. > The buffer itself holds data from a file. If the file > is mmap'ed (or is executable code), then the page is > mapped into user space. If the file is accessed using > read/write, then it isn't. Thanks for the reply. If for a page, that is mapped to a process, page->buffers is non-null then does that mean that the page contains data from the mmapped file ? and one more thing, in function try_to_swap_out() the page for which page->buffers is non-null then we do not free the page then. Why dont we free the buffers then ? Thanks, Raghu > > Hope this helps, > Ravi. > > __________________________________ > Do you Yahoo!? > Yahoo! SiteBuilder - Free, easy-to-use web site design software > http://sitebuilder.yahoo.com > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
