> On Thu, 20 Apr 2023 13:16:21 +0200 Lorenzo Bianconi wrote:
> > @@ -727,17 +729,21 @@ static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
> > goto drop;
> >
> > /* Allocate skb head */
> > - page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
> > + if (rq->page_pool)
>
> There's some condition under which we can get to XDP enabled but no
> pool?
ack, since we destroy the page_pool after disabling the rq napi we can get rid
of 'if (rq->page_pool)' checks here.
>
> > + page = page_pool_dev_alloc_pages(rq->page_pool);
> > if (!page)
> > goto drop;
> >
> > nskb = build_skb(page_address(page), PAGE_SIZE);
> > if (!nskb) {
> > - put_page(page);
> > + page_pool_put_full_page(rq->page_pool, page, false);
>
> You can recycle direct, AFAIU the basic rule of thumb is that it's
> always safe to recycle direct from the context which allocates from
> the pool.
ack, I will fix it.
>
> > goto drop;
> > }
> >
> > skb_reserve(nskb, VETH_XDP_HEADROOM);
> > + skb_copy_header(nskb, skb);
> > + skb_mark_for_recycle(nskb);
> > +
> > size = min_t(u32, skb->len, max_head_size);
> > if (skb_copy_bits(skb, 0, nskb->data, size)) {
> > consume_skb(nskb);
> > @@ -745,16 +751,17 @@ static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
> > }
> > skb_put(nskb, size);
> >
> > - skb_copy_header(nskb, skb);
> > head_off = skb_headroom(nskb) - skb_headroom(skb);
> > skb_headers_offset_update(nskb, head_off);
> >
> > /* Allocate paged area of new skb */
> > off = size;
> > len = skb->len - off;
> > + page = NULL;
>
> Why do you clear the page pointer?
since we do not need 'if (rq->page_pool)' checks anymore we can get rid of it.
Regards,
Lorenzo
>
> --
> pw-bot: cr
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