Question on migrate_disabe/enable()

[Zhang, Qiang]

Hello Peterz, tglx

I have some questions about migrate_disabe/enable(),  in the past migrate_disabe/enable() is replaced by preempt_disable/enable() in no RT system.

And now migrate_disabe/enable() has its own implementation, I want to know in migrate_disabe/enable() critical area is blocking allowed?  

If allowed, There's a blockage in migrate_disabe/enable() critical area, and this time if CPU going offline，offline time will be longer. Is this normal phenomenon？

Thanks
Qiang