| Message ID | 1268153703-4186-2-git-send-email-sgruszka@redhat.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Tue, 2010-03-09 at 08:55 -0800, Stanislaw Gruszka wrote: > Access to fp->tx_bd_prod is protected by __netif_tx_lock, so we do not > need any barrier for that. > > Update of fp->tx_bd_cons in bnx2x_tx_int() is not protected by lock, but > barrier() nor smb_mb() in bnx2x_tx_avail() not guarantee we will see > values that is written on other cpu. Ordering issues between > netif_tx_stop_queue(), netif_tx_queue_stopped(), fp->tx_bd_cons = bd_cons > and bnx2x_tx_avail() are already handled by smp_mb() in bnx2x_tx_int() > and bnx2x_start_xmit(). > > Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Eilon Greenstein <eilong@broadcom.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: "Eilon Greenstein" <eilong@broadcom.com> Date: Wed, 10 Mar 2010 18:00:57 +0200 > On Tue, 2010-03-09 at 08:55 -0800, Stanislaw Gruszka wrote: >> Access to fp->tx_bd_prod is protected by __netif_tx_lock, so we do not >> need any barrier for that. >> >> Update of fp->tx_bd_cons in bnx2x_tx_int() is not protected by lock, but >> barrier() nor smb_mb() in bnx2x_tx_avail() not guarantee we will see >> values that is written on other cpu. Ordering issues between >> netif_tx_stop_queue(), netif_tx_queue_stopped(), fp->tx_bd_cons = bd_cons >> and bnx2x_tx_avail() are already handled by smp_mb() in bnx2x_tx_int() >> and bnx2x_start_xmit(). >> >> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> > Signed-off-by: Eilon Greenstein <eilong@broadcom.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/bnx2x_main.c b/drivers/net/bnx2x_main.c index 9fc0f6a..ae62b67 100644 --- a/drivers/net/bnx2x_main.c +++ b/drivers/net/bnx2x_main.c @@ -893,7 +893,6 @@ static inline u16 bnx2x_tx_avail(struct bnx2x_fastpath *fp) u16 prod; u16 cons; - barrier(); /* Tell compiler that prod and cons can change */ prod = fp->tx_bd_prod; cons = fp->tx_bd_cons;
Access to fp->tx_bd_prod is protected by __netif_tx_lock, so we do not need any barrier for that. Update of fp->tx_bd_cons in bnx2x_tx_int() is not protected by lock, but barrier() nor smb_mb() in bnx2x_tx_avail() not guarantee we will see values that is written on other cpu. Ordering issues between netif_tx_stop_queue(), netif_tx_queue_stopped(), fp->tx_bd_cons = bd_cons and bnx2x_tx_avail() are already handled by smp_mb() in bnx2x_tx_int() and bnx2x_start_xmit(). Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> --- drivers/net/bnx2x_main.c | 1 - 1 files changed, 0 insertions(+), 1 deletions(-)