Linux page cache doubt

[Arun Ramakrishnan <ramakria@xxxxxxxxxxxxxxxxxx>]

Hi All,
   I recently read that all fs codes actually do I/O to and from the 
pagecache and then the dirty pages are synced to the disk later using 
the bdflush daemon.This approach has some performance problems when I/O 
is done thru write calls rather than mmap.    I was just curious whether 
this path was modified when XFS was written ( ie how cud such a approach 
even work in case of  jounalled file system when log operations are 
needed bfore the data gets written out).
I am kinda newbie into kernel hacking and so i am sorry if my question 
sounds dumb.
Cheers,
Arun.

--
Arun Ramakrishnan 
Graduate Research Assistant / Sys Admin
Linux Cluster I/O Lab
The Ohio State University

Ph : (614)-294-5523 (H)
    (614)-292-4634 (O)