On Wed, Oct 14, 2026 at 09:49:54PM +0000, [email protected] wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s)
> to consider:
> - [High] mana: unratelimited netdev_warn in __mana_start_xmit causes log spam
> under XDP load
> --
>
> commit a6a9466a25f553494605c439f140071b9b0b7068
> Author: Hamza Mahfooz <[email protected]>
>
> net: mana: add BQL support
>
> MANA doesn't support byte queue limits, so each TX queue can hold 256
> WQEs by default, and up to 16384, of up to 64 KB TSO packets, before the
> qdisc layer sees any backpressure. This adds latency to all the flows
> sharing a queue, and defeats AQM qdiscs such as fq_codel. This patch
> adds BQL support by reporting the bytes queued and completed to BQL,
> except for XDP_TX and XDP_REDIRECT frames.
>
> > diff --git a/drivers/net/ethernet/microsoft/mana/mana_bpf.c
> > b/drivers/net/ethernet/microsoft/mana/mana_bpf.c
> > index 484f061bc75e4..7c55f8724441d 100644
> > --- a/drivers/net/ethernet/microsoft/mana/mana_bpf.c
> > +++ b/drivers/net/ethernet/microsoft/mana/mana_bpf.c
> > @@ -21,7 +21,7 @@ void mana_xdp_tx(struct sk_buff *skb, struct net_device
> > *ndev)
> > ndevtxq = netdev_get_tx_queue(ndev, txq_idx);
> > __netif_tx_lock(ndevtxq, smp_processor_id());
> >
> > - rc = mana_start_xmit(skb, ndev);
> > + rc = __mana_start_xmit(skb, ndev, true);
>
> [Severity: High]
> Does this allow unratelimited log spam under heavy XDP load?
>
> XDP traffic directly calls the transmit path here without checking or
> honoring the stopped queue state. If the Send Queue fills up,
> __mana_start_xmit() unconditionally calls mana_gd_post_work_request(),
> which can return -ENOSPC.
>
> When it fails, __mana_start_xmit() prints an unratelimited warning:
>
> if (err) {
> (void)skb_dequeue_tail(&txq->pending_skbs);
> mana_unmap_skb(skb, apc);
> netdev_warn(ndev, "Failed to post TX OOB: %d\n", err);
> goto free_sgl_ptr;
> }
>
> If XDP blasts packets into a full queue, could this print for every dropped
> packet and cause severe log spew?
>
This issue predates this patch (it was actually introduced when XDP
support was first added with commit ed5356b53f07 ("net: mana: Add XDP
support")), so it should be fixed as a seperate patch directed at the
net tree.
> > __netif_tx_unlock(ndevtxq);
>
> [ ... ]
>
> --
> Sashiko AI review ยท
> https://sashiko.dev/#/patchset/[email protected]?part=1
