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From: Jesper Dangaard Brouer <brouer@redhat.com>
To: "Toke Høiland-Jørgensen" <toke@redhat.com>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Alexei Starovoitov" <ast@kernel.org>,
	"David Miller" <davem@davemloft.net>,
	"Björn Töpel" <bjorn.topel@gmail.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	brouer@redhat.com
Subject: Re: [PATCH bpf-next 1/2] xdp: Move devmap bulk queue into struct net_device
Date: Fri, 10 Jan 2020 17:08:24 +0100	[thread overview]
Message-ID: <20200110170824.7379adbf@carbon> (raw)
In-Reply-To: <157866612285.432695.6722430952732620313.stgit@toke.dk>

On Fri, 10 Jan 2020 15:22:02 +0100
Toke Høiland-Jørgensen <toke@redhat.com> wrote:

> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 2741aa35bec6..1b2bc2a7522e 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
[...]
> @@ -1993,6 +1994,8 @@ struct net_device {
>  	spinlock_t		tx_global_lock;
>  	int			watchdog_timeo;
>  
> +	struct xdp_dev_bulk_queue __percpu *xdp_bulkq;
> +
>  #ifdef CONFIG_XPS
>  	struct xps_dev_maps __rcu *xps_cpus_map;
>  	struct xps_dev_maps __rcu *xps_rxqs_map;

We need to check that the cache-line for this location in struct
net_device is not getting updated (write operation) from different CPUs.

The test you ran was a single queue single CPU test, which will not
show any regression for that case.

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer


  parent reply	other threads:[~2020-01-10 16:08 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-10 14:22 [PATCH bpf-next 0/2] xdp: Introduce bulking for non-map XDP_REDIRECT Toke Høiland-Jørgensen
2020-01-10 14:22 ` [PATCH bpf-next 1/2] xdp: Move devmap bulk queue into struct net_device Toke Høiland-Jørgensen
2020-01-10 15:03   ` Björn Töpel
2020-01-10 15:26     ` Toke Høiland-Jørgensen
2020-01-10 16:08   ` Jesper Dangaard Brouer [this message]
2020-01-10 22:34     ` Toke Høiland-Jørgensen
2020-01-10 22:46       ` Eric Dumazet
2020-01-10 23:16         ` Toke Høiland-Jørgensen
2020-01-10 14:22 ` [PATCH bpf-next 2/2] xdp: Use bulking for non-map XDP_REDIRECT Toke Høiland-Jørgensen
2020-01-10 15:15   ` Björn Töpel
2020-01-10 15:30     ` Toke Høiland-Jørgensen
2020-01-10 15:54       ` Björn Töpel
2020-01-10 15:57         ` Toke Høiland-Jørgensen

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