netdev - Re: [Patch net] netns: correct gfp flags for alloc

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Message-ID: <1425001791.5565.180.camel@edumazet-glaptop2.roam.corp.google.com>
Date:	Thu, 26 Feb 2015 17:49:51 -0800
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Cong Wang <xiyou.wangcong@...il.com>
Cc:	netdev@...r.kernel.org, Nicolas Dichtel <nicolas.dichtel@...nd.com>
Subject: Re: [Patch net] netns: correct gfp flags for alloc_netid()

On Thu, 2015-02-26 at 16:54 -0800, Cong Wang wrote:
> This fixes the following kernel warning:
> 
>  ===============================
>  [ INFO: suspicious RCU usage. ]
>  3.19.0+ #805 Tainted: G        W      
>  -------------------------------
>  include/linux/rcupdate.h:538 Illegal context switch in RCU read-side critical section!
>  
>  other info that might help us debug this:
>  

I do not think this is the right way to fix this.

Bug is that rtnl_dump_ifinfo() should not use rcu_read_lock(), as RTNL
is held : GFP_KERNEL allocations in control path should be the golden
rule.

I guess I should have reverted e67f88dd12f6 completely
instead of the partial revert (2907c35ff647080)



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