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| author |   LEROY Christophe <christophe.leroy@c-s.fr> | 2014-10-07 15:05:02 +0200 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2014-10-08 16:01:41 -0400 |
| commit | d43a396af0f54740c4f491a066d249b7d7467593 (patch) | |
| tree | 5a49f7bcc87106c58aab068841c7e869db659126 /drivers/net/ethernet/freescale/fs_enet/mac-scc.c | |
| parent | net: fs_enet: Remove non NAPI RX (diff) | |
| download | linux-dev-d43a396af0f54740c4f491a066d249b7d7467593.tar.xz linux-dev-d43a396af0f54740c4f491a066d249b7d7467593.zip | |
net: fs_enet: Add NAPI TX
When using a MPC8xx as a router, 'perf' shows a significant time spent in
fs_enet_interrupt() and fs_enet_start_xmit().
'perf annotate' shows that the time spent in fs_enet_start_xmit is indeed spent
between spin_unlock_irqrestore() and the following instruction, hence in
interrupt handling. This is due to the TX complete interrupt that fires after
each transmitted packet.
This patch modifies the handling of TX complete to use NAPI.
With this patch, my NAT router offers a throughput improved by 21%
Original performance:
[root@localhost tmp]# scp toto pgs:/tmp
toto 100% 256MB 2.8MB/s 01:31
Performance with the patch:
[root@localhost tmp]# scp toto pgs:/tmp
toto 100% 256MB 3.4MB/s 01:16
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/freescale/fs_enet/mac-scc.c')
| -rw-r--r-- | drivers/net/ethernet/freescale/fs_enet/mac-scc.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/net/ethernet/freescale/fs_enet/mac-scc.c b/drivers/net/ethernet/freescale/fs_enet/mac-scc.c index 90b3b19b7cd3..41aa0b475ca0 100644 --- a/drivers/net/ethernet/freescale/fs_enet/mac-scc.c +++ b/drivers/net/ethernet/freescale/fs_enet/mac-scc.c @@ -116,6 +116,7 @@ static int do_pd_setup(struct fs_enet_private *fep) } #define SCC_NAPI_RX_EVENT_MSK (SCCE_ENET_RXF | SCCE_ENET_RXB) +#define SCC_NAPI_TX_EVENT_MSK (SCCE_ENET_TXF | SCCE_ENET_TXB) #define SCC_RX_EVENT (SCCE_ENET_RXF) #define SCC_TX_EVENT (SCCE_ENET_TXB) #define SCC_ERR_EVENT_MSK (SCCE_ENET_TXE | SCCE_ENET_BSY) @@ -130,6 +131,7 @@ static int setup_data(struct net_device *dev) fep->scc.htlo = 0; fep->ev_napi_rx = SCC_NAPI_RX_EVENT_MSK; + fep->ev_napi_tx = SCC_NAPI_TX_EVENT_MSK; fep->ev_rx = SCC_RX_EVENT; fep->ev_tx = SCC_TX_EVENT | SCCE_ENET_TXE; fep->ev_err = SCC_ERR_EVENT_MSK; @@ -398,6 +400,30 @@ static void napi_disable_rx(struct net_device *dev) C16(sccp, scc_sccm, SCC_NAPI_RX_EVENT_MSK); } +static void napi_clear_tx_event(struct net_device *dev) +{ + struct fs_enet_private *fep = netdev_priv(dev); + scc_t __iomem *sccp = fep->scc.sccp; + + W16(sccp, scc_scce, SCC_NAPI_TX_EVENT_MSK); +} + +static void napi_enable_tx(struct net_device *dev) +{ + struct fs_enet_private *fep = netdev_priv(dev); + scc_t __iomem *sccp = fep->scc.sccp; + + S16(sccp, scc_sccm, SCC_NAPI_TX_EVENT_MSK); +} + +static void napi_disable_tx(struct net_device *dev) +{ + struct fs_enet_private *fep = netdev_priv(dev); + scc_t __iomem *sccp = fep->scc.sccp; + + C16(sccp, scc_sccm, SCC_NAPI_TX_EVENT_MSK); +} + static void rx_bd_done(struct net_device *dev) { /* nothing */ @@ -471,6 +497,9 @@ const struct fs_ops fs_scc_ops = { .napi_clear_rx_event = napi_clear_rx_event, .napi_enable_rx = napi_enable_rx, .napi_disable_rx = napi_disable_rx, + .napi_clear_tx_event = napi_clear_tx_event, + .napi_enable_tx = napi_enable_tx, + .napi_disable_tx = napi_disable_tx, .rx_bd_done = rx_bd_done, .tx_kickstart = tx_kickstart, .get_int_events = get_int_events, |