From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH] net: cgroup: fix access the unallocated memory in
 netprio cgroup
Date: Tue, 10 Jul 2012 11:15:07 +0200
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Cc: nhorman@tuxdriver.com, davem@davemloft.net,
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To: Gao feng <gaofeng@cn.fujitsu.com>
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On Tue, 2012-07-10 at 16:53 +0800, Gao feng wrote:
> > Hi Gao
> > 
> > Is it still needed to call update_netdev_tables() from write_priomap() ?
> > 
> 
> Yes, I think it's needed,because read_priomap will show all of the net devices,
> 
> But we may add the netdev after create a netprio cgroup, so the new added netdev's
> priomap will not be allocated. if we don't call update_netdev_tables in write_priomap,
> we may access this unallocated memory.
> 

I realize my question was not clear.

If we write in write_priomap() a field of a single netdevice,
why should we allocate memory for all netdevices on the machine ?

So the question was : Do we really need to call
update_netdev_tables(alldevs), instead of extend_netdev_table(dev)