SoftIRQs and Fast Packet Processing on Linux network

I have been reading about performance tuning of Linux to get the fastest packet processing times when receiving financial market data. I see that when the NIC receives a packet, it puts it in memory via DMA, then raises a HardIRQ - which in turn sets some NAPI settings and raises a SoftIRQ. The SoftIRQ then uses NAPI/device drivers to read data from the RX Buffers via polling, but this is only run for some limited time (net.core.netdev_budget, defaulted to 300 packets). These are in reference to a real server running ubuntu, with a solarflare NIC My questions are below: 1. If each HardIRQ raises a SoftIRQ, and the Device Driver reads multiple packets in 1 go (netdev_budget), what happens to the SoftIRQs raised by each of the packets that were drained from the RX buffer in 1 go (Each pack received will raise a hard and then soft irq)? Are these queued? 2. Why does the NAPI use polling to drain the RX_buffer? The system has just generated a SoftIRQ and is reading the RX buffer, then why the polling? 3. Presumably, draining of the RX_Buffer via the softirq, will only happen from 1 specific RX_Buffer and not across multiple RX_Buffers? If so, then increasing the netdev_budget can delay the processing/draining of other RX_buffers? Or can this be mitigated by assigning different RX_buffers to different cores? 4. There are settings to ensure that HardIRQs are immediately raised and handled. However, SoftIRQs may be processed at a later time. Are there settings/configs to ensure that SoftIRQs related to network RX are also handled at top priority and without delays?