Re: [PATCH tip/sched/urgent] sched: revert 498657a478c60be092208422fefa9c7b248729c2

[Avi Kivity <avi@redhat.com>]

On 11/30/2009 01:02 PM, Tejun Heo wrote:
> 498657a478c60be092208422fefa9c7b248729c2 incorrectly assumed that
> preempt wasn't disabled around context_switch() and thus was fixing
> imaginary problem.  It also broke kvm because it depended on
> ->sched_in() to be called with irq enabled so that it can do smp calls
> from there.
>
> Revert the incorrect commit and add comment describing different
> contexts under with the two callbacks are invoked.
>
>    *    notifier: struct preempt_notifier for the task being preempted
>    *    next: the task that's kicking us out
> + *
> + * Please note that sched_in and out are called under different
> + * contexts.  sched_in is called with rq lock held and irq disabled
> + * while sched_out is called without rq lock and irq enabled.
>    */
>    

Is this transposed?  sched_in must be called with interrupts enabled for 
the kvm IPI to work.

-- 
error compiling committee.c: too many arguments to function