RE: [PATCH net-next 06/11] net: fec: transmit XDP frames in bulk
From: Wei Fang <wei.fang@nxp.com>
Date: 2026-01-14 09:57:37
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On Tue, Jan 13, 2026 at 11:29:34AM +0800, Wei Fang wrote:quoted
Currently, the driver writes the ENET_TDAR register for every XDP frame to trigger transmit start. Frequent MMIO writes consume more CPU cycles and may reduce XDP TX performance, so transmit XDP frames in bulk. Signed-off-by: Wei Fang <wei.fang@nxp.com> ---Did you test light loading case? Any unexpected latency happen? sometime missing trigger is hard to find when heavy loading.
I don't think a missing trigger event will occur. The driver doesn't wait until the number of packets reaches a certain threshold before triggering the transmission. The driver receives some packets in each batch, the number is not fixed, but there is a threshold. After putting these packets on the TX BD ring, transmission is triggered. Therefore, each batch will definitely trigger transmission.