Documentation/networking/scaling.rst

27 Contemporary NICs support multiple receive and transmit descriptor queues
399 which transmit queue to use when transmitting a packet on a multi-queue
402 to hardware transmit queue(s).
407 exclusively to a subset of CPUs, where the transmit completions for
412 transmit queue). Secondly, cache miss rate on transmit completion is
418 This mapping is used to pick transmit queue based on the receive
420 queues can be mapped to a set of transmit queues (many:many), although
422 on the same queue associations for transmit and receive. This is useful for
428 transmit queue corresponding to the associated receive queue has benefits
432 application cleans up the packets during the busy poll, transmit completion
436 XPS is configured per transmit queue by setting a bitmap of
437 CPUs/receive-queues that may use that queue to transmit. The reverse
438 mapping, from CPUs to transmit queues or from receive-queues to transmit
442 for the socket connection for a match in the receive queue-to-transmit queue
447 into the set. When selecting the transmit queue based on receive queue(s)
448 map, the transmit device is not validated against the receive device as it
453 This transmit queue is used for subsequent packets sent on the flow to
458 there are no outstanding packets in the flow, so the transmit queue can
470 to transmit queue can be inspected and configured using sysfs:
491 with the CPU that processes transmit completions for that queue
492 (transmit interrupts).
494 For transmit queue selection based on receive queue(s), XPS has to be
495 explicitly configured mapping receive-queue(s) to transmit queue(s). If the
496 user configuration for receive-queue map does not apply, then the transmit