[PATCH] pktcdvd: Don't waste kernel memory
Allocate memory for read-gathering at open time, when it is known just how
much memory is needed. This avoids wasting kernel memory when the real packet
size is smaller than the maximum packet size supported by the driver. This is
always the case when using DVD discs.
Signed-off-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/pktcdvd.h b/include/linux/pktcdvd.h
index d1c9c4a..1623da8 100644
--- a/include/linux/pktcdvd.h
+++ b/include/linux/pktcdvd.h
@@ -170,7 +170,7 @@
#error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
#endif
#define PACKET_MAX_SIZE 32
-#define PAGES_PER_PACKET (PACKET_MAX_SIZE * CD_FRAMESIZE / PAGE_SIZE)
+#define FRAMES_PER_PAGE (PAGE_SIZE / CD_FRAMESIZE)
#define PACKET_MAX_SECTORS (PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
enum packet_data_state {
@@ -219,7 +219,7 @@
atomic_t io_errors; /* Number of read/write errors during IO */
struct bio *r_bios[PACKET_MAX_SIZE]; /* bios to use during data gathering */
- struct page *pages[PAGES_PER_PACKET];
+ struct page *pages[PACKET_MAX_SIZE / FRAMES_PER_PAGE];
int cache_valid; /* If non-zero, the data for the zone defined */
/* by the sector variable is completely cached */