Le 08/05/15 08:41, Madalin Bucur a écrit : > This introduces the Freescale Data Path Acceleration Architecture > (DPAA) Ethernet driver (dpaa_eth) that builds upon the DPAA QMan, > BMan, PAMU and FMan drivers to deliver Ethernet connectivity on > the Freescale DPAA QorIQ platforms. > > Signed-off-by: Madalin Bucur <madalin.bu...@freescale.com> > --- [snip] > + > +if FSL_DPAA_ETH > + > +config FSL_DPAA_CS_THRESHOLD_1G > + hex "Egress congestion threshold on 1G ports" > + range 0x1000 0x10000000 > + default "0x06000000"
This sounds like something you would want to be able to configure at runtime, either via private sysfs attributes, or better, using ethtool and either a newly introduced set of tunables, or creating a private driver API for this. > + ---help--- > + The size in bytes of the egress Congestion State notification > threshold on 1G ports. > + The 1G dTSECs can quite easily be flooded by cores doing Tx in a > tight loop > + (e.g. by sending UDP datagrams at "while(1) speed"), > + and the larger the frame size, the more acute the problem. > + So we have to find a balance between these factors: > + - avoiding the device staying congested for a prolonged time > (risking > + the netdev watchdog to fire - see also the tx_timeout > module param); > + - affecting performance of protocols such as TCP, which > otherwise > + behave well under the congestion notification mechanism; > + - preventing the Tx cores from tightly-looping (as if the > congestion > + threshold was too low to be effective); > + - running out of memory if the CS threshold is set too high. > + > +config FSL_DPAA_CS_THRESHOLD_10G > + hex "Egress congestion threshold on 10G ports" > + range 0x1000 0x20000000 > + default "0x10000000" > + ---help --- > + The size in bytes of the egress Congestion State notification > threshold on 10G ports. > + > +config FSL_DPAA_INGRESS_CS_THRESHOLD > + hex "Ingress congestion threshold on FMan ports" > + default "0x10000000" > + ---help--- > + The size in bytes of the ingress tail-drop threshold on FMan ports. > + Traffic piling up above this value will be rejected by QMan and > discarded by FMan. Same here. -- Florian -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
