3 ms·
If I read that correctly the data is still on the NIC. The CPU receives an interrupt - notifying it of a new packet, which it then decides to drop? Thus the CPU
by penagwin 8y ago
If I read that correctly the data is still on the NIC. The CPU receives an interrupt - notifying it of a new packet, which it then decides to drop? Thus the CPU is the one dropping packets, but the data (most of it at least) is still on the NIC.
Please correct me if I'm wrong.
- emmericp 8y agoThis all happens after the packet is transferred over PCIe to the CPU/memory (even the interrupt happens after DMA transfer). Otherwise the XDP code wouldn't have access to the packet to filter it; the example doesn't just drop all packets, it drops all packets matching a /24 subnet which happens to be all packets here ;)
- penagwin 8y agoAh ok! I was kinda confused by that xD