> -----Original Message----- > From: Andrew Lunn <andrew@xxxxxxx> > Sent: 2023年7月5日 7:48 > To: Wei Fang <wei.fang@xxxxxxx> > Cc: davem@xxxxxxxxxxxxx; edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx; > pabeni@xxxxxxxxxx; ast@xxxxxxxxxx; daniel@xxxxxxxxxxxxx; > hawk@xxxxxxxxxx; john.fastabend@xxxxxxxxx; Shenwei Wang > <shenwei.wang@xxxxxxx>; Clark Wang <xiaoning.wang@xxxxxxx>; > netdev@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; > linux-kernel@xxxxxxxxxxxxxxx; bpf@xxxxxxxxxxxxxxx > Subject: Re: [PATCH net 2/3] net: fec: recycle pages for transmitted XDP frames > > > /* Save skb pointer */ > > - txq->tx_skbuff[index] = skb; > > + txq->tx_buf[index].skb = skb; > > What about txq->tx_buf[index].type ? > we restore the buffer type to FEC_TXBUF_T_SKB when recycling the buffer descriptor, so there is no need to set it again here. > > @@ -862,7 +860,7 @@ static int fec_enet_txq_submit_tso(struct > fec_enet_priv_tx_q *txq, > > } > > > > /* Save skb pointer */ > > - txq->tx_skbuff[index] = skb; > > + txq->tx_buf[index].skb = skb; > > here as well. > > > + /* restore default tx buffer type: FEC_TXBUF_T_SKB */ > > + txq->tx_buf[i].type = FEC_TXBUF_T_SKB; > > Seems error prone. It would be safer to explicitly set it next to > assigning .skb/.xdp. I also considered this method, but in the case when skb has frags or TSO, we only need to set skb pointer for the first txq->tx_buf, but we need to explicitly set the type for all txq->tx_buf corresponding to the skb. This may confuse others. As for your concern about being error-prone. I don't think it should be, I reset the type to FEC_TXBUF_T_SKB in all places where buffers are recycled or cleared. > > Andrew
