On Mon, Jan 11, 2016 at 10:38:28PM +0000, Seymour, Shane M wrote: > I have some concerns and suggestions for you about this. > > What's to stop someone in user space from requesting an arbitrarily large number of CPU # cache locations that the kernel needs to allocate memory to track and each time the task migrates to a new CPU it needs to update them all? Could you use it to dramatically slow down a system/task switching? Should there be a ulimit type value or a sysctl setting to limit the number that you're allowed to register per-task? The documented behavior of the syscall allows only one location per thread, so the kernel can track that one and only address rather easily in the task_struct. Allowing dynamic allocation definitely doesn't seem like a good idea. - Josh Triplett -- 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
