David Miller <da...@davemloft.net> writes: > From: Måns Rullgård <m...@mansr.com> > Date: Wed, 11 Nov 2015 00:40:09 +0000 > >> When the DMA complete interrupt arrives, the next chain should be >> kicked off as quickly as possible, and I don't see why that would >> benefit from being done in napi context. > > NAPI isn't about low latency, it's about fairness and interrupt > mitigation. > > You probably don't even realize that all of the TX SKB freeing you do > in the hardware interrupt handler end up being actually processed by a > scheduled software interrupt anyways. > > So you are gaining almost nothing by not doing TX completion in NAPI > context, whereas by doing so you would be gaining a lot including > more simplified locking or even the ability to do no locking at all.
TX completion is separate from restarting the DMA, and moving that to NAPI may well be a good idea. Should I simply napi_schedule() if the hardware indicates TX is complete and do the cleanup in the NAPI poll function? -- Måns Rullgård m...@mansr.com -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
