Re: [PATCH 50/51] net/core/flow.c: Fix CPU hotplug callbackregistration

From: David Miller
Date: Fri Feb 07 2014 - 00:19:59 EST

From: David Miller <davem@xxxxxxxxxxxxx>
Date: Thu, 06 Feb 2014 20:39:21 -0800 (PST)

> From: "Srivatsa S. Bhat" <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
> Date: Thu, 06 Feb 2014 03:43:46 +0530
>> Subsystems that want to register CPU hotplug callbacks, as well as perform
>> initialization for the CPUs that are already online, often do it as shown
>> below:
> ...
>> This is wrong, since it is prone to ABBA deadlocks involving the
>> cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
>> with CPU hotplug operations).
>> Instead, the correct and race-free way of performing the callback
>> registration is:
> ...
>> Fix the code in net/core/flow.c by using this latter form of callback
>> registration.
>> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
>> Cc: Li RongQing <>
>> Cc: Sasha Levin <sasha.levin@xxxxxxxxxx>
>> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>> Cc: Chris Metcalf <cmetcalf@xxxxxxxxxx>
>> Cc: netdev@xxxxxxxxxxxxxxx
>> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
> Applied.

I just realized that this has a dependency not in the 'net'
tree, so I reverted and assume you will merge this with the
patch that provides the necessary interface(s).

Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
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