net: mvneta: prefetch next rx descriptor instead of current one
Currently, the mvneta driver tries to prefetch the current Rx
descriptor during read. Tests have shown that prefetching the
next one instead increases general performance by about 1% on
HTTP traffic.
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index aa3a4f7..c7b37e0 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -611,6 +611,7 @@
int rx_desc = rxq->next_desc_to_proc;
rxq->next_desc_to_proc = MVNETA_QUEUE_NEXT_DESC(rxq, rx_desc);
+ prefetch(rxq->descs + rxq->next_desc_to_proc);
return rxq->descs + rx_desc;
}
@@ -1442,7 +1443,6 @@
u32 rx_status;
int rx_bytes, err;
- prefetch(rx_desc);
rx_done++;
rx_filled++;
rx_status = rx_desc->status;