Re: [PATCH] Make RCU task_struct safe for oprofile

[Ingo Molnar]

* Paul E. McKenney <paulmck@xxxxxxxxxx> wrote:

> Hello!
> 
> Applying RCU to the task structure broke oprofile, because 
> free_task_notify() can now be called from softirq.  This means that 
> the task_mortuary lock must be acquired with irq disabled in order to 
> avoid intermittent self-deadlock.  Since irq is now disabled, the 
> critical section within process_task_mortuary() has been restructured 
> to be O(1) in order to maximize scalability and minimize realtime 
> latency degradation.
> 
> Kudos to Wu Fengguang for finding this problem!

thanks, i applied this to the -rt tree.

	Ingo
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