On Tue, 20 Oct 2015 14:26:34 -0700 Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: > I'm not a scheduler person, so I don't know. But "don't run me unless > I'm isolated" seems like a design that will, at best, only ever work > by dumb luck. You have to disable migration, avoid other runnable > tasks, hope that the kernel keeps working the way it did when you > wrote the patch, hope you continue to get lucky enough that you ever > get to user mode in the first place, etc. Since it only makes sense to run one isolated task per cpu (not more than one on the same CPU), I wonder if we should add a new interface for this, that would force everything else off the CPU that it requests. That is, you bind a task to a CPU, and then change it to SCHED_ISOLATED (or what not), and the kernel will force all other tasks off that CPU. Well, we would still have kernel threads, but that's a different matter. Also, doesn't RCU need to have a few ticks go by before it can safely disable itself from userspace? I recall something like that. Paul? -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
