Look-ahead handling of page faults in I/O operations

A method for data transfer, comprising:

• receiving multiple data packets in a network interface controller (NIC) coupled to a host processor, the data packets including at least first and second packets respectively containing first and second data directed to respective first and second virtual addresses in a memory of the host processor;
• while processing the first data in the NIC and before processing the second data from the second packet, detecting that a first page containing the first virtual address and a second page containing the second virtual address are swapped out of the memory on a mass-storage device;
• responsively to detecting that the first and second pages are swapped out of the memory, swapping both the first and second pages into the host memory together, from the mass-storage device, before processing the second data from the second packet;
• and
• after swapping the first and second pages into the host memory, writing the first and second data to the first and second pages.

A network interface controller (NIC), comprising:

• a host interface for connection to a host processor having a host memory and running an operating system;
• a network interface configured to receive multiple data packets from a network, including at least first and second packets respectively containing first and second data directed to respective first and second virtual addresses in the host memory;
• and
• processing circuitry, which is configured to process the data packets so as to detect, while processing the first data from the first packet and before processing the second data from the second packet, that a first page containing the first virtual address and a second page containing the second virtual address are swapped out of the memory on a mass-storage device,
• wherein the processing circuitry is configured, responsively to detecting that the first and second pages are swapped out of the memory and before processing the second data from the second packet, to cause the operating system to swap both the first and second pages into the host memory together, from the mass-storage device, and to write the first and second data to the first and second pages after the first and second pages have been swapped into the host memory.