question on priority imbalance in Linux SMP scheduler!

["Thirupathiah Annapureddy" <writetothiru@xxxxxxxxx>]

Hi All,

 

I am new to linux kernel. I was refering to an interesting article titled "Inside the Linux scheduler", published at http://www.ibm.com/developerworks/linux/library/l-scheduler/.

 

I have a questions related to "priority imbalance". The article mentions that each CPU has a runqueue made up of 140 priority lists i.e. per CPU ready queue. Hence it is possible that a runnable high priority task waits for a CPU in ready queue while a lower priority task is running on a different CPU. This can lead to priority imbalance/priority inversion. How does linux SMP scheduler handle this priority imbalance?

 

Thanks in advance for you answer.
Regards