From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH 07/10] decnet: use RCU to find network devices
Date: Tue, 10 Nov 2009 19:43:21 +0100
Message-ID: <4AF9B449.6040708@gmail.com>
References: <20091110175446.280423729@vyatta.com> <20091110175647.615305929@vyatta.com>
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Cc: David Miller <davem@davemloft.net>,
	Christine Caulfield <christine.caulfield@googlemail.com>,
	Hannes Eder <hannes@hanneseder.net>,
	Alexey Dobriyan <adobriyan@gmail.com>,
	Steven Whitehouse <swhiteho@redhat.com>,
	netdev@vger.kernel.org, linux-decnet-users@lists.sourceforge.net
To: Stephen Hemminger <shemminger@vyatta.com>
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Stephen Hemminger a =E9crit :
> When showing device statistics use RCU rather than read_lock(&dev_bas=
e_lock)
> Compile tested only.
>=20
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
>=20
> --- a/net/decnet/dn_dev.c	2009-11-10 09:30:55.557376454 -0800
> +++ b/net/decnet/dn_dev.c	2009-11-10 09:40:03.847005394 -0800
> @@ -856,9 +856,7 @@ int dn_dev_bind_default(__le16 *addr)
>  	dev =3D dn_dev_get_default();
>  last_chance:
>  	if (dev) {
> -		read_lock(&dev_base_lock);
>  		rv =3D dn_dev_get_first(dev, addr);
> -		read_unlock(&dev_base_lock);
>  		dev_put(dev);
>  		if (rv =3D=3D 0 || dev =3D=3D init_net.loopback_dev)
>  			return rv;
> @@ -1323,18 +1321,18 @@ static inline int is_dn_dev(struct net_d


I dont understand this part. Why previous locking can be avoided ?