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authorEilon Greenstein <eilong@broadcom.com>2009-03-02 07:59:24 +0000
committerDavid S. Miller <davem@davemloft.net>2009-03-02 22:32:38 -0800
commit6044735d8ddd96bf23cf975bae8729c65479aa14 (patch)
tree36fe481362fe7b5ee26edb55c2dcc52d96cc24ca
parent0d1a8d2d7dd9f6588ed9544a9aa88fd9bd9467d3 (diff)
bnx2x: Reduce the likelihood of smb_mb
As the comment explains, this smb_mb is needed only if the queue is stopped (which is unlikely) so the barrier can be moved to that location Signed-off-by: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/bnx2x_main.c15
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/net/bnx2x_main.c b/drivers/net/bnx2x_main.c
index 5954bed60652..fbd0f88fc81b 100644
--- a/drivers/net/bnx2x_main.c
+++ b/drivers/net/bnx2x_main.c
@@ -916,18 +916,19 @@ static void bnx2x_tx_int(struct bnx2x_fastpath *fp, int work)
fp->tx_pkt_cons = sw_cons;
fp->tx_bd_cons = bd_cons;
- /* Need to make the tx_bd_cons update visible to start_xmit()
- * before checking for netif_tx_queue_stopped(). Without the
- * memory barrier, there is a small possibility that start_xmit()
- * will miss it and cause the queue to be stopped forever.
- */
- smp_mb();
-
/* TBD need a thresh? */
if (unlikely(netif_tx_queue_stopped(txq))) {
__netif_tx_lock(txq, smp_processor_id());
+ /* Need to make the tx_bd_cons update visible to start_xmit()
+ * before checking for netif_tx_queue_stopped(). Without the
+ * memory barrier, there is a small possibility that
+ * start_xmit() will miss it and cause the queue to be stopped
+ * forever.
+ */
+ smp_mb();
+
if ((netif_tx_queue_stopped(txq)) &&
(bp->state == BNX2X_STATE_OPEN) &&
(bnx2x_tx_avail(fp) >= MAX_SKB_FRAGS + 3))