netdev - Re: [PATCH v28 01/20] net: Introduce direct data placement tcp offload

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CANn89i+y4cKYezwQ6Zr0fr=d6ky8K20E9zYOz=EUiRi_vY8e_g@mail.gmail.com>
Date: Thu, 5 Jun 2025 05:44:40 -0700
From: Eric Dumazet <edumazet@...gle.com>
To: Aurelien Aptel <aaptel@...dia.com>
Cc: linux-nvme@...ts.infradead.org, netdev@...r.kernel.org, sagi@...mberg.me, 
	hch@....de, kbusch@...nel.org, axboe@...com, chaitanyak@...dia.com, 
	davem@...emloft.net, kuba@...nel.org, Boris Pismenny <borisp@...dia.com>, 
	aurelien.aptel@...il.com, smalin@...dia.com, malin1024@...il.com, 
	ogerlitz@...dia.com, yorayz@...dia.com, galshalom@...dia.com, 
	mgurtovoy@...dia.com, tariqt@...dia.com, gus@...labora.com, pabeni@...hat.com, 
	dsahern@...nel.org, ast@...nel.org, jacob.e.keller@...el.com
Subject: Re: [PATCH v28 01/20] net: Introduce direct data placement tcp offload

On Thu, Jun 5, 2025 at 4:55 AM Aurelien Aptel <aaptel@...dia.com> wrote:
>
> Eric Dumazet <edumazet@...gle.com> writes:
> > Adding one bit in all skbs for such a narrow case is not very convincing to me.
> >
> > I would prefer a disable/enable bit in the receiving socket, or a
> > global static key.
>
> We can move the bit to the socket, within the sock_read_rx cacheline group:
>
>
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -420,7 +420,7 @@ struct sock {
>  #endif
>         u8                      sk_userlocks;
>         int                     sk_rcvbuf;
> -
> +       bool                    sk_no_condense;
>         struct sk_filter __rcu  *sk_filter;
>         union {
>                 struct socket_wq __rcu  *sk_wq;
>
>
> And then check for it in skb_condense().
> We are still evaluating it but it looks fine for us.
> Would that work for you?

This is a slow path check, you can use one bit after sk_no_check_rx,
because we have a hole there.