Subject: Re: [PATCH 2.6 1/5]: Fix locking in __qdisc_destroy rcu-callback

From: Patrick McHardy <[email-masked]>
Date: Wed, 04 Aug 2004 21:53:28 +0200

David S. Miller wrote:

>On Tue, 03 Aug 2004 17:20:36 +0200
>Patrick McHardy <[email-masked]> wrote:
>  
>
>>I'm not sure if RCU callback can be scheduled while the kernel is
>>
>>running in process context, so this may be unneccessary.
>>    
>>
>
>RCU callbacks run via tasklets, and thus in softirq context,
>thus your locking changes to _bh() are indeed necessary.
>  
>
I meant because in my understanding of RCU the quintescent state is
not reached while the CPU is running kernel code, so the callback can't
be scheduled. A previously scheduled callback should finish before
further kernel code is run in process context.

Regards
Patrick