| Message ID | 0609ecd8fa7ecaa99a386e17f47027349cc3fdda.1472033140.git.christophe.leroy@c-s.fr (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On 08/24/2016 03:36 AM, Christophe Leroy wrote: > Measurement shows that on a MPC8xx running at 132MHz, the optimal > limit is 112: > * 114 bytes packets are processed in 147 TB ticks with higher copybreak > * 114 bytes packets are processed in 148 TB ticks with lower copybreak > * 128 bytes packets are processed in 154 TB ticks with higher copybreak > * 128 bytes packets are processed in 148 TB ticks with lower copybreak > * 238 bytes packets are processed in 172 TB ticks with higher copybreak > * 238 bytes packets are processed in 148 TB ticks with lower copybreak > > However it might be different on other processors > and/or frequencies. So it is useful to make it configurable. > > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> > --- > drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c | 8 +++++--- > include/linux/fs_enet_pd.h | 1 - > 2 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c > index addcae6..b59bbf8 100644 > --- a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c > +++ b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c > @@ -60,6 +60,10 @@ module_param(fs_enet_debug, int, 0); > MODULE_PARM_DESC(fs_enet_debug, > "Freescale bitmapped debugging message enable value"); > > +static int rx_copybreak = 240; > +module_param(rx_copybreak, int, S_IRUGO | S_IWUSR); > +MODULE_PARM_DESC(rx_copybreak, "Receive copy threshold"); There is an ethtool tunable knob for copybreak now, which you should prefer over a module parameter, see drivers/net/ethernet/cisco/enic/enic_ethtool.c
diff --git a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c index addcae6..b59bbf8 100644 --- a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c +++ b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c @@ -60,6 +60,10 @@ module_param(fs_enet_debug, int, 0); MODULE_PARM_DESC(fs_enet_debug, "Freescale bitmapped debugging message enable value"); +static int rx_copybreak = 240; +module_param(rx_copybreak, int, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(rx_copybreak, "Receive copy threshold"); + #ifdef CONFIG_NET_POLL_CONTROLLER static void fs_enet_netpoll(struct net_device *dev); #endif @@ -84,7 +88,6 @@ static int fs_enet_napi(struct napi_struct *napi, int budget) { struct fs_enet_private *fep = container_of(napi, struct fs_enet_private, napi); struct net_device *dev = fep->ndev; - const struct fs_platform_info *fpi = fep->fpi; cbd_t __iomem *bdp; struct sk_buff *skb, *skbn; int received = 0; @@ -232,7 +235,7 @@ static int fs_enet_napi(struct napi_struct *napi, int budget) pkt_len = CBDR_DATLEN(bdp) - 4; /* remove CRC */ fep->stats.rx_bytes += pkt_len + 4; - if (pkt_len <= fpi->rx_copybreak) { + if (pkt_len <= rx_copybreak) { /* +2 to make IP header L1 cache aligned */ skbn = netdev_alloc_skb(dev, pkt_len + 2); if (skbn != NULL) { @@ -905,7 +908,6 @@ static int fs_enet_probe(struct platform_device *ofdev) fpi->rx_ring = 32; fpi->tx_ring = 64; - fpi->rx_copybreak = 240; fpi->napi_weight = 17; fpi->phy_node = of_parse_phandle(ofdev->dev.of_node, "phy-handle", 0); if (!fpi->phy_node && of_phy_is_fixed_link(ofdev->dev.of_node)) { diff --git a/include/linux/fs_enet_pd.h b/include/linux/fs_enet_pd.h index 77d783f..376600e 100644 --- a/include/linux/fs_enet_pd.h +++ b/include/linux/fs_enet_pd.h @@ -138,7 +138,6 @@ struct fs_platform_info { int rx_ring, tx_ring; /* number of buffers on rx */ __u8 macaddr[ETH_ALEN]; /* mac address */ - int rx_copybreak; /* limit we copy small frames */ int napi_weight; /* NAPI weight */ int use_rmii; /* use RMII mode */
Measurement shows that on a MPC8xx running at 132MHz, the optimal limit is 112: * 114 bytes packets are processed in 147 TB ticks with higher copybreak * 114 bytes packets are processed in 148 TB ticks with lower copybreak * 128 bytes packets are processed in 154 TB ticks with higher copybreak * 128 bytes packets are processed in 148 TB ticks with lower copybreak * 238 bytes packets are processed in 172 TB ticks with higher copybreak * 238 bytes packets are processed in 148 TB ticks with lower copybreak However it might be different on other processors and/or frequencies. So it is useful to make it configurable. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c | 8 +++++--- include/linux/fs_enet_pd.h | 1 - 2 files changed, 5 insertions(+), 4 deletions(-)