Hi Leo,
On Mon, Dec 12, 2016 at 03:22:05PM +0800, Leo Yan wrote:
For LITTLE cluster "overutilized" flag, it only works after whole system is "overutilized". This is for 6 big tasks case, but for 4 middle tasks case, LITTLE cluster "overutilized" flag doesn't set; so if there have several tasks on LITTLE cluster, we cannot rely on LITTLE cluster "overutilized" flag to spread tasks within LITTLE cluster [6].
I personally think this may not an issue, due we can reply on EAS core algorithm to select best CPU within cluster. So we doesn't rely on "overutilized" flag to spread tasks in LITTLE cluster. And after whole system is "overutilized", then we disable "EAS" path and use SMP traditional load balance. Agree?
For 4 middle-sized tasks the EAS-code should hopefully spread the tasks at wake-up. I'm more concerned about big tasks on the little cluster as those would only be migrated by the 'misfit'-code. IIUC, in case we have n_big_tasks < n_little_cpus currently scheduled on the little cluster, 'overutilized' won't be set at the root_domain and hence the big cluster won't try to pull any of the big tasks. IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.