CPU isolation comes with a handful of cpumasks to help determine which CPUs can
sanely be interrupted, but those are not always checked when sending an IPI, nor
is it always obvious wether a given cross-call could be omitted (or delayed) if
targeting an isolated CPU.
A grep for "on_each_cpu()" and "smp_call()" on a mainline kernel yields about
350 results. This slot will be about discussing ways to detect and classify
those (remote data retrieval, system wide synchronization...), if and how to
patch them and where to draw the line(s) on system administrator configuration
vs what is expected of the kernel.
|I agree to abide by the anti-harassment policy||Yes|