Hi Mike,
On 6 April 2014 14:00, Mike Galbraith umgwanakikbuti@gmail.com wrote:
I wonder if adding a quiesce switch is really necessary.
Seems to me that if you don't have load balancing turned off, you can't be very concerned about perturbation, so this should be tied into the load balancing on/off switch as an extension to isolating cores from the #1 perturbation source, the scheduler.
Its more about not doing any background activities on these CPU which can be avoided. So, even if a add_timer() is issued from these isolated CPUs, it should goto the set chosen for doing background activity, unless add_timer_on() has been issued, in which case user wants that code to execute on the isolated core.
Probably, yes, people would be disabling load_balancing between these cpusets to avoid migration of tasks to isolated core as well.. Atleast we are using it :)
I also didn't notice a check for is_cpu_exclusive() at a glance, which would be a bug, but one that would go away if this additional isolation were coupled to the existing isolation switch.
Yeah, there is no check for that. But I didn't got your point completely. Why do I need to check for exclusivity on the isolated CPUs? So, that same CPU isn't isolated as well as non-isolated on two separate sets?
Thanks for your feedback.
-- viresh