[patch] clarify AIO_EVENTS_OFFSET constant

[Chen, Kenneth W]

A clean up patch: I think it is a lot easier to read AIO_EVENTS_OFFSET
as an offset because of aio_ring at the beginning of a head page, instead
of doing arithmetic of (event on 2nd page - event on 1st page).


Signed-off-by: Ken Chen <kenneth.w.chen@xxxxxxxxx>


diff -Nurp linux-2.6.18/fs/aio.c linux-2.6.18.ken/fs/aio.c
--- linux-2.6.18/fs/aio.c	2006-09-19 20:42:06.000000000 -0700
+++ linux-2.6.18.ken/fs/aio.c	2006-10-12 13:33:09.000000000 -0700
@@ -173,9 +173,8 @@ static int aio_setup_ring(struct kioctx 
 /* aio_ring_event: returns a pointer to the event at the given index from
  * kmap_atomic(, km).  Release the pointer with put_aio_ring_event();
  */
-#define AIO_EVENTS_PER_PAGE	(PAGE_SIZE / sizeof(struct io_event))
-#define AIO_EVENTS_FIRST_PAGE	((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event))
-#define AIO_EVENTS_OFFSET	(AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE)
+#define AIO_EVENTS_PER_PAGE  (PAGE_SIZE / sizeof(struct io_event))
+#define AIO_EVENTS_OFFSET    (sizeof(struct aio_ring) / sizeof(struct io_event))
 
 #define aio_ring_event(info, nr, km) ({					\
 	unsigned pos = (nr) + AIO_EVENTS_OFFSET;			\

-
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