Hi

This is a patch for counting bounce pages.
With this, pages for bounce buffer is coutned and shown in /proc/meminfo.

Because pages for bounce buffer are not counted in anywhere,
sometimes it seems that there are many leaked pages.
ex)
I found 1.7GB of bounce buffer pages in a crash dump of ia64 kernel,
which was passed me to check memory usage. :(

BTW, I'm not sure whether # of bounce buffer should be includeded in Buffers:
of /proc/meminfo.


-- Kame <kamezawa.hiroyu@jp.fujitsu.com>