From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <dada1@cosmosbay.com>
Subject: Re: regression: unregister_netdev() unusably slow
Date: Mon, 25 May 2009 00:07:07 +0200
Message-ID: <4A19C50B.9040304@cosmosbay.com>
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Cc: Denys Fedoryschenko <denys@visp.net.lb>, netdev@vger.kernel.org
To: Benjamin LaHaise <bcrl@lhnet.ca>
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Benjamin LaHaise a =E9crit :
> On Sun, May 24, 2009 at 11:42:17PM +0200, Eric Dumazet wrote:
>> (But vlan case might be litle bit more expensive than your case, sin=
ce we call
>> synchronize_net() three times (once in unregister_vlan_dev(), and tw=
ice in rollback_registered()
>=20
> I did try commenting out the synchronize_net() calls in rollback_regi=
stered(),=20
> but that had almost no effect on the rate of interface deletion.  50m=
s is=20
> still way too expensive.
>=20
> 		-ben

Maybe your HZ is too low ? Changing to 1000 HZ helps a lot

Also your hotplug config might do strange things at device removal ?

What distro do you use ?