On Tue, 10 Sept 2024 at 16:20, Srivats P <pstavirs@xxxxxxxxx> wrote: > > > For AF_XDP (in ZC or copy mode), the IRQ-CPU affinity plays a role in > > the RX direction to bind a CPU core to a particular NIC queue (mapping > > the CPU core to the NIC queue's IRQ). > > > > My question is does the IRQ or IRQ-CPU affinity play any role in the > > TX direction? > > > > An xsk is specific to a NIC queue and assuming there is only one core > > doing TX on that xsk, is there some IRQ/CPU configuration recommended > > for better performance? > > > > Does the recommendation change if busy-polling mode is used or not > > used? ZC or non-ZC? > > Any advice or recommendation about IRQ-CPU affinity or usage for AF_XDP TX path? For copy-mode, the majority of work is done in process context and just a minority of the work is performed in the interrupt routine. This is also true for zero-copy mode with busy-poll. In zero-copy mode without busy-poll however, it is the opposite. So irq affinity mainly matters in zero-copy mode without busy-poll. > Srivats >
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