netdev - Re: [PATCH net-next 1/4] net: allow alloc_skb_with

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Message-ID: <64c95169b8de2_1cc1c42947@willemb.c.googlers.com.notmuch>
Date: Tue, 01 Aug 2023 14:39:37 -0400
From: Willem de Bruijn <willemdebruijn.kernel@...il.com>
To: Eric Dumazet <edumazet@...gle.com>, 
 Willem de Bruijn <willemdebruijn.kernel@...il.com>
Cc: "David S . Miller" <davem@...emloft.net>, 
 Jakub Kicinski <kuba@...nel.org>, 
 Paolo Abeni <pabeni@...hat.com>, 
 Willem de Bruijn <willemb@...gle.com>, 
 Tahsin Erdogan <trdgn@...zon.com>, 
 netdev@...r.kernel.org, 
 eric.dumazet@...il.com
Subject: Re: [PATCH net-next 1/4] net: allow alloc_skb_with_frags() to
 allocate bigger packets

Eric Dumazet wrote:
> On Tue, Aug 1, 2023 at 8:10 PM Eric Dumazet <edumazet@...gle.com> wrote:
> >
> > On Tue, Aug 1, 2023 at 7:56 PM Willem de Bruijn
> > <willemdebruijn.kernel@...il.com> wrote:
> > >
> >
> > > Thanks for the explanation. For @data_len == 5000, you would want to
> > > allocate an order-1?
> >
> > Presumably we could try a bit harder, I will send a V2.
> 
> I will squash the following part:
> 
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index 0ac70a0144a7c1f4e7824ddc19980aee73e4c121..c6f98245582cd4dd01a7c4f5708163122500a4f0
> 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -6233,7 +6233,7 @@ struct sk_buff *alloc_skb_with_frags(unsigned
> long header_len,
>         while (data_len) {
>                 if (nr_frags == MAX_SKB_FRAGS - 1)
>                         goto failure;
> -               while (order && data_len < (PAGE_SIZE << order))
> +               while (order && PAGE_ALIGN(data_len) < (PAGE_SIZE << order))
>                         order--;
> 
>                 if (order) {

Thanks. Clearly not a serious concern. v1 looks great to me too. Was
just trying to understand fully.