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stmmac mitigation and ethtool coalesce parameters

DISCUSSION Giuseppe CAVALLARO 1 participant 1 message Aug 22, 2012

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Hello
I'm reworking the mitigation schema in the stmmac and removing the old and dead STMMAC_TIMER code.

On new chips we have an HW RX-Watchdog that can be used for mitigating the Rx-interrupts and first results look promising.

Before posting the patches I have a doubt about the ethtool coalesce parameters to use in the driver to tune the following parameters:

- On Rx-side I have:
a parameter that is the RI Watchdog Timer count. It indicates the number of system clock cycles.

- On Tx-side, the mitigation schema I'm using is based on a SW timer that calls the tx function (stmmac_tx) to reclaim the resource after transmitting the frames.
Also there is another parameter (like a threshold) used to program the descriptors avoiding to set the interrupt on completion bit in when the frame is sent (xmit). This means that the stmmac_tx can be
called by the ISR too. This approach is showing really good figures
as well.

so I wonder which are the appropriate ethtool coalesce parameters to use? Or could I tune them by using sysfs entries?

Welcome advice.

Peppe