Dynamic Core Isolation in multicore CPU's

mav_indian · 01-09-2015, 12:20 AM

Currently CPU or CORE isolation is done by passing "ioslcpu" as an bootarg to the kernel. Is it possible to do dynamic cpu isolation ?

syg00 · 01-09-2015, 12:48 AM

cgroups allows you to establish (sub-)sets of CPUs and assign pids to them to isolate workload(s).
Not particularly well documented - try this for background.

sundialsvcs · 01-11-2015, 09:35 AM

Also, never forget that cores are never really isolated from anything else that occupies "the same silicon chip and the same set of supporting printed-circuit-board circuitry." They are not equivalent to "a separate cluster-member processor," nor even "a separate CPU." All of their accesses to the outside world are in-competition with those of all other cores.

mav_indian · 01-14-2015, 02:12 PM

Thank you for the quick replies. While I am trying out few experiments with cpusets, was looking for any data comparing cpusets with isolcpu and what would be the better method to provide CPU isolation?

nishajain29 · 04-05-2015, 09:05 PM

Did you find any data to compare cpuset with isolcpu to benchmark which one is the better method to provide CPU isolation? Did cpuset prove better than isolcpu in your experiments? I am also considering replacing isolcpu with cpuset but was not sure if it is at par with isolcpu. Any information would be very helpful.

mav_indian · 04-06-2015, 12:11 AM

I tried out experiments with cpuset's and found no issues with them. I dont have any performance data but I would recommend using cpusets over "ioslcpu" as ioslcpu is a static boot time config whereas cpusets can be changed on the fly via the cpu hotplug feature which comes along with cgroups. I think going forward ioslcpu will get deprecated as cpuset provides you the same functionality with the dynamic modification capability. And as containers take over the way systems gets designed CPUSET's will the one to go for.