From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Saeed Mahameed <saeedm@mellanox.com>
Cc: "dsahern@gmail.com" <dsahern@gmail.com>,
"Toke Høiland-Jørgensen" <thoiland@redhat.com>,
"hawk@kernel.org" <hawk@kernel.org>,
"virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>,
"borkmann@iogearbox.net" <borkmann@iogearbox.net>,
"Tariq Toukan" <tariqt@mellanox.com>,
"john.fastabend@gmail.com" <john.fastabend@gmail.com>,
"mst@redhat.com" <mst@redhat.com>,
"jakub.kicinski@netronome.com" <jakub.kicinski@netronome.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"jasowang@redhat.com" <jasowang@redhat.com>,
"davem@davemloft.net" <davem@davemloft.net>,
"makita.toshiaki@lab.ntt.co.jp" <makita.toshiaki@lab.ntt.co.jp>,
brouer@redhat.com, "Toke Høiland-Jørgensen" <toke@toke.dk>
Subject: Resource management for ndo_xdp_xmit (Was: [PATCH net] virtio_net: Account for tx bytes and packets on sending xdp_frames)
Date: Thu, 7 Feb 2019 08:48:15 +0100 [thread overview]
Message-ID: <20190207084815.1e8bd817@carbon> (raw)
In-Reply-To: <140ecbe1e25f54f90d859cc696c4119aa96bc6eb.camel@mellanox.com>
On Wed, 6 Feb 2019 00:06:33 +0000 Saeed Mahameed <saeedm@mellanox.com> wrote:
> On Mon, 2019-02-04 at 19:13 -0800, David Ahern wrote:
[...]
> >
> > mlx5 needs some work. As I recall it still has the bug/panic
> > removing xdp programs - at least I don't recall seeing a patch for
> > it.
>
> Only when xdp_redirect to mlx5, and removing the program while
> redirect is happening, this is actually due to a lack of
> synchronization means between different drivers, we have some ideas
> to overcome this using a standard XDP API, or just use a hack in mlx5
> driver which i don't like:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux.git/commit/?h=topic/xdp-redirect-fix&id=a3652d03cc35fd3ad62744986c8ccaca74c9f20c
>
> I will be working on this towards the end of this week.
Toke and I have been discussing how to solve this.
The main idea for fixing this is to tie resource allocation to interface
insertion into interface maps (kernel/bpf/devmap.c). As the =devmap=
already have the needed synchronisation mechanisms and steps for safely
adding and removing =net_devices= (e.g. stopping RX side, flushing
remaining frames, waiting RCU period before freeing objects, etc.)
As described here:
https://github.com/xdp-project/xdp-project/blob/master/xdp-project.org#better-ndo_xdp_xmit-resource-management
--Jesper
next prev parent reply other threads:[~2019-02-07 7:48 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-31 11:40 [PATCH net] virtio_net: Account for tx bytes and packets on sending xdp_frames Toshiaki Makita
2019-01-31 15:25 ` Michael S. Tsirkin
2019-01-31 17:45 ` David Miller
2019-01-31 20:15 ` Jesper Dangaard Brouer
2019-02-01 1:53 ` Toshiaki Makita
2019-02-02 21:27 ` David Ahern
2019-02-04 11:53 ` Jesper Dangaard Brouer
2019-02-05 3:13 ` David Ahern
2019-02-06 0:06 ` Saeed Mahameed
2019-02-06 13:48 ` Jesper Dangaard Brouer
2019-02-06 15:52 ` Jakub Kicinski
2019-02-07 7:48 ` Jesper Dangaard Brouer [this message]
2019-02-07 19:08 ` Resource management for ndo_xdp_xmit (Was: [PATCH net] virtio_net: Account for tx bytes and packets on sending xdp_frames) Saeed Mahameed
2019-02-08 16:55 ` Toke Høiland-Jørgensen
2019-02-08 22:49 ` Saeed Mahameed
2019-02-08 23:17 ` Saeed Mahameed
2019-02-09 0:18 ` Saeed Mahameed
2019-02-09 2:05 ` Jakub Kicinski
2019-02-09 16:56 ` Toke Høiland-Jørgensen
2019-02-09 16:56 ` Toke Høiland-Jørgensen
2019-02-08 16:02 ` [PATCH net] virtio_net: Account for tx bytes and packets on sending xdp_frames Jesper Dangaard Brouer
2019-04-18 14:24 ` Stats for XDP actions (was: Re: [PATCH net] virtio_net: Account for tx bytes and packets on sending xdp_frames) Toke Høiland-Jørgensen
2019-04-21 0:16 ` Stats for XDP actions David Ahern
2019-06-20 20:42 ` Toke Høiland-Jørgensen
2019-06-21 0:42 ` David Ahern
2019-06-21 13:57 ` Toke Høiland-Jørgensen
2019-02-04 4:18 ` [PATCH net] virtio_net: Account for tx bytes and packets on sending xdp_frames David Miller
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