From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nicolas Dichtel <nicolas.dichtel@dev.6wind.com>
Subject: Re: [PATCH] netns: remove useless synchronize_net()
Date: Fri, 06 Feb 2009 14:50:53 +0100
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To: David Miller <davem@davemloft.net>
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Le 06.02.2009 08:45, David Miller a =E9crit :
> From: Nicolas Dichtel <nicolas.dichtel@dev.6wind.com>
> Date: Thu, 05 Feb 2009 11:21:22 +0100
>=20
>> In dev_change_net_namespace(), synchronize_net() is called at the
>> end of the function, but there is no reason (no deletion occurs).
>>
>> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
>=20
> It is necessary to make sure all cpus stop looking at the
> previous namespace the device was attached to, and only
> see the new mapping.
I didn't really understand why it is 'necessary'.
If namespace is destroyed after this function, then cleanup_net() will =
ensure=20
that nobody is looking at it
There is only two callers, rtnetlink and default_device_exit().


Thank you for your answer,
Nicolas

>=20
> That's why this function has two synchronize_net() calls.