ixgbe: Only use double buffering if page size is less than 8K
This change makes it so that we do not use double buffering if the page
size is larger than 4K. Instead we will simply walk through the page using
up to 3K per receive, and if we receive less than we only move the offset
by that amount. We will free the page when there is no longer any space
left that we can use instead of checking the page count to see if we can
cycle back to the start.
The main motivation behind this is to avoid the unnecessary truesize cost
for using a half page when most packets are 2K or smaller. With this new
approach the largest possible truesize for a page fragment will be 3K when
PAGE_SIZE is larger than 4K.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
index b9623e9..fd2bc69 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
@@ -78,6 +78,9 @@
/* Supported Rx Buffer Sizes */
#define IXGBE_RXBUFFER_256 256 /* Used for skb receive header */
+#define IXGBE_RXBUFFER_2K 2048
+#define IXGBE_RXBUFFER_3K 3072
+#define IXGBE_RXBUFFER_4K 4096
#define IXGBE_MAX_RXBUFFER 16384 /* largest size for a single descriptor */
/*
@@ -293,16 +296,25 @@
* this is twice the size of a half page we need to double the page order
* for FCoE enabled Rx queues.
*/
-#if defined(IXGBE_FCOE) && (PAGE_SIZE < 8192)
+static inline unsigned int ixgbe_rx_bufsz(struct ixgbe_ring *ring)
+{
+#ifdef IXGBE_FCOE
+ if (test_bit(__IXGBE_RX_FCOE, &ring->state))
+ return (PAGE_SIZE < 8192) ? IXGBE_RXBUFFER_4K :
+ IXGBE_RXBUFFER_3K;
+#endif
+ return IXGBE_RXBUFFER_2K;
+}
+
static inline unsigned int ixgbe_rx_pg_order(struct ixgbe_ring *ring)
{
- return test_bit(__IXGBE_RX_FCOE, &ring->state) ? 1 : 0;
-}
-#else
-#define ixgbe_rx_pg_order(_ring) 0
+#ifdef IXGBE_FCOE
+ if (test_bit(__IXGBE_RX_FCOE, &ring->state))
+ return (PAGE_SIZE < 8192) ? 1 : 0;
#endif
+ return 0;
+}
#define ixgbe_rx_pg_size(_ring) (PAGE_SIZE << ixgbe_rx_pg_order(_ring))
-#define ixgbe_rx_bufsz(_ring) ((PAGE_SIZE / 2) << ixgbe_rx_pg_order(_ring))
struct ixgbe_ring_container {
struct ixgbe_ring *ring; /* pointer to linked list of rings */