netdev - Re: [PATCH bpf-next 2/4] xsk: allow AF_XDP sockets to receive packets directly from a queue

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

Message-ID: <875zkzn2pj.fsf@toke.dk>
Date:   Tue, 08 Oct 2019 08:58:16 +0200
From:   Toke Høiland-Jørgensen <toke@...hat.com>
To:     Sridhar Samudrala <sridhar.samudrala@...el.com>,
        magnus.karlsson@...el.com, bjorn.topel@...el.com,
        netdev@...r.kernel.org, bpf@...r.kernel.org,
        sridhar.samudrala@...el.com, intel-wired-lan@...ts.osuosl.org,
        maciej.fijalkowski@...el.com, tom.herbert@...el.com
Subject: Re: [PATCH bpf-next 2/4] xsk: allow AF_XDP sockets to receive packets directly from a queue

Sridhar Samudrala <sridhar.samudrala@...el.com> writes:

>  int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
>  		    struct bpf_prog *xdp_prog)
>  {
>  	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
>  	struct bpf_map *map = READ_ONCE(ri->map);
> +	struct xdp_sock *xsk;
> +
> +	xsk = xdp_get_direct_xsk(ri);
> +	if (xsk)
> +		return xsk_rcv(xsk, xdp);

This is a new branch and a read barrier in the XDP_REDIRECT fast path.
What's the performance impact of that for non-XSK redirect?

-Toke