Core affinity and scheduling

bsrajan · 08-25-2014, 07:14 AM

In SMP linux running in a dual-core CPU, how does the scheduling work in the following conditions for a process whose affinity is set to both Cores?
1. Core 0 is 100% utilized and Core 1 is ~50% utilized (read as CPU cycles available)
2. Core 1 is 100% utilized and Core 0 is ~50% utilized (read as CPU cycles available)
3. Both Core 0 & Core 1 are almost IDLE

Ygrex · 08-27-2014, 05:43 AM

doubt if there can be definite answers, will see

meantime you can check this article, for example:
http://lwn.net/Articles/80911/

the process will tend to stay on the same CPU once moved into its run queue, taking into consideration cache affinity, physical topology, actual imbalance (50% is not a scheduler metric)