--- "Raghu R. Arur" <rra2002@aria.ncl.cs.columbia.edu> wrote: > Hi, > > Please help me to understand this better. each buffer > has a buffer > head. the b_page of buffer_head points to the page that > contains the > 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. 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/
