2015-06-17 12:00 GMT-07:00 Nicolae Rosia <nicolae.ro...@gmail.com>: > Hi, > > On Wed, Jun 17, 2015 at 9:54 PM, Jaeden Amero <jaeden.am...@ni.com> wrote: >> On 06/17/2015 11:09 AM, Nicolae Rosia wrote: >> The times we've seen tons of interrupts on Ethernet with interrupts >> routed through the PL was when the FPGA was unprogrammed (or in the >> process of being reprogrammed), or was configured with the interrupt >> line tied to asserted. >> >> In the latter case, Linux would eventually stop handling any more >> interrupts for that port due to the interrupt storm. >> > This isn't the case. The FPGA is programmed, and indeed I'm using the > second MAC routed through PL to SFP. > The interesting thing is that I'm seeing the exact behavior on the > other side (another Zynq7 board), with eth0 having lots of interrupts. > It seems that the interface receiving packets doesn't have a high IRQ > activity in contrast to the one sending packets.
Typically, NAPI is used at the receive side of the Ethernet NIC/driver to lower the hard/soft interrupt context switch, although there is nothing that prevent you to implement a similar scheme for the transmit side. Usually, for transmit you will be submitting one packet for transmission and get a completion interrupt, so without interrupt coalescing (software or hardware) you can end-up with 1 interrupt per packet transmitted. -- 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
