Messages in this thread | | | From | Ilias Apalodimas <> | Date | Fri, 27 Jan 2023 09:15:08 +0200 | Subject | Re: [net PATCH] skb: Do mix page pool and page referenced frags in GRO |
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Thanks Alexander!
On Fri, 27 Jan 2023 at 01:13, Jakub Kicinski <kuba@kernel.org> wrote: > > On Thu, 26 Jan 2023 11:06:59 -0800 Alexander Duyck wrote: > > From: Alexander Duyck <alexanderduyck@fb.com> > > > > GSO should not merge page pool recycled frames with standard reference > > counted frames. Traditionally this didn't occur, at least not often. > > However as we start looking at adding support for wireless adapters there > > becomes the potential to mix the two due to A-MSDU repartitioning frames in > > the receive path. There are possibly other places where this may have > > occurred however I suspect they must be few and far between as we have not > > seen this issue until now. > > > > Fixes: 53e0961da1c7 ("page_pool: add frag page recycling support in page pool") > > Reported-by: Felix Fietkau <nbd@nbd.name> > > Signed-off-by: Alexander Duyck <alexanderduyck@fb.com> > > Exciting investigation! > Felix, out of curiosity - the impact of loosing GRO on performance is > not significant enough to care? We could possibly try to switch to > using the frag list if we can't merge into frags safely. > > > diff --git a/net/core/gro.c b/net/core/gro.c > > index 506f83d715f8..4bac7ea6e025 100644 > > --- a/net/core/gro.c > > +++ b/net/core/gro.c > > @@ -162,6 +162,15 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) > > struct sk_buff *lp; > > int segs; > > > > + /* Do not splice page pool based packets w/ non-page pool > > + * packets. This can result in reference count issues as page > > + * pool pages will not decrement the reference count and will > > + * instead be immediately returned to the pool or have frag > > + * count decremented. > > + */ > > + if (p->pp_recycle != skb->pp_recycle) > > + return -ETOOMANYREFS; > > > > /* pairs with WRITE_ONCE() in netif_set_gro_max_size() */ > > gro_max_size = READ_ONCE(p->dev->gro_max_size); > > > > > > > Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
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