Re: [Intel-wired-lan] [PATCH iwl-next 3/3] ice: switch to Page Pool

[Michal Kubiak <michal.kubiak@intel.com>]

On Mon, Jul 07, 2025 at 03:58:37PM -0700, Jacob Keller wrote:
> 
> 
> On 7/4/2025 9:18 AM, Michal Kubiak wrote:
> > @@ -1075,16 +780,17 @@ void ice_clean_ctrl_rx_irq(struct ice_rx_ring *rx_ring)
> >  static int ice_clean_rx_irq(struct ice_rx_ring *rx_ring, int budget)

[...]

> > @@ -1144,27 +841,35 @@ static int ice_clean_rx_irq(struct ice_rx_ring *rx_ring, int budget)
> >  		if (ice_is_non_eop(rx_ring, rx_desc))
> >  			continue;
> >  
> > -		ice_get_pgcnts(rx_ring);
> >  		xdp_verdict = ice_run_xdp(rx_ring, xdp, xdp_prog, xdp_ring, rx_desc);
> >  		if (xdp_verdict == ICE_XDP_PASS)
> >  			goto construct_skb;
> > -		total_rx_bytes += xdp_get_buff_len(xdp);
> > -		total_rx_pkts++;
> >  
> > -		ice_put_rx_mbuf(rx_ring, xdp, &xdp_xmit, ntc, xdp_verdict);
> > +		if (xdp_verdict & (ICE_XDP_TX | ICE_XDP_REDIR))
> > +			xdp_xmit |= xdp_verdict;
> > +		total_rx_bytes += xdp_get_buff_len(&xdp->base);
> > +		total_rx_pkts++;
> >  
> > +		xdp->data = NULL;
> > +		rx_ring->first_desc = ntc;
> > +		rx_ring->nr_frags = 0;
> >  		continue;
> >  construct_skb:
> > -		skb = ice_build_skb(rx_ring, xdp);
> > +		skb = xdp_build_skb_from_buff(&xdp->base);
> > +
> >  		/* exit if we failed to retrieve a buffer */
> >  		if (!skb) {
> >  			rx_ring->ring_stats->rx_stats.alloc_page_failed++;
> 
> This is not your fault, but we've been incorrectly incrementing
> alloc_page_failed here instead of alloc_buf_failed.
> 

Sure. It's a good idea to fix it while we're rewriting the Rx path.
Will be addressed in v2.

> >  			xdp_verdict = ICE_XDP_CONSUMED;
> 
> xdp_verdict is no longer used, so I don't think we need to modify it
> further here. It was previously being used as part of the call to
> ice_put_rx_mbuf.
> 

You're right. I'll remove it in v2.

> > +			xdp->data = NULL;
> > +			rx_ring->first_desc = ntc;
> > +			rx_ring->nr_frags = 0;
> > +			break;
> >  		}
> > -		ice_put_rx_mbuf(rx_ring, xdp, &xdp_xmit, ntc, xdp_verdict);
> >  
> > -		if (!skb)
> > -			break;
> > +		xdp->data = NULL;
> > +		rx_ring->first_desc = ntc;
> > +		rx_ring->nr_frags = 0;
> >  
> 
> The failure case for !skb does the same as this, so would it make sense
> to move this block up to before !skb and just check the skb pointer
> afterwards?
> 

Yeah. Together with Olek we re-organized the logic here, so in v2 it
should be simplified.

> >  		stat_err_bits = BIT(ICE_RX_FLEX_DESC_STATUS0_RXE_S);
> >  		if (unlikely(ice_test_staterr(rx_desc->wb.status_error0


Thanks,
Michal