TAKE - cluster write changes

[Ananth Ananthanarayanan <ananth@xxxxxxxxxxxxxxxxxx>]

Date:  Thu Jul  6 14:51:05 PDT 2000
Workarea:  dbear.engr.sgi.com:/build2/ananth/slinx24-xfs

The following file(s) were checked into:
  bonnie.engr.sgi.com:/isms/slinx/2.4.0-test1-xfs


Modid:  2.4.0-test1-xfs:slinx:65802a
linux/fs/pagebuf/page_buf_io.c - 1.9
http://oss.sgi.com/cgi-bin/cvsweb.cgi/linux-2.4-xfs/linux/fs/pagebuf/page_buf_io.c.diff?r1=text&tr1=1.9&r2=text&tr2=1.8&f=h
        - Use local variables to hold pages to cluster instead of a global 
array,
          now that the flush path and the page_daemon can cluster pages.
          Also, make the size of cluster scale with the amount of memory
          in the system.