On Mon, 14 Mar 2011 16:05:24 +0200 Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> wrote: > +Overview > +-------- > + > +Every task_struct has timer_slack_ns value. This value uses to round up > +poll() and select() timeout values. This feature can be useful in > +mobile environment where combined wakeups are desired. > + > +Originally, prctl() was the only way to change timer slack value of > +a process. So you was not able change timer slack value of another > +process. > + > +cgroup subsys "timer_slack" implements timer slack controller. It > +provides a way to set minimal timer slack value for a group of tasks. > +If a task belongs to a cgroup with minimal timer slack value higher than > +task's value, cgroup's value will be applied. > + > +Timer slack controller allows to implement setting timer slack value of > +a process based on a policy. For example, you can create foreground and > +background cgroups and move tasks between them based on system state. (quoting myself from last time) Why do we need a cgroup for this as opposed to (say) inheritance over fork(), or a system-wide knob, or a per-process/threadgroup knob, or just leaving the existing code as-is? Presumably you felt that a cgroup approach is better for manageability, but you didn't tell us about this and you didn't explore alternative ways of solving the problem-which-you-didn't-describe. I'm still having trouble seeing why we should merge this. Who will use it, and for what reason and what benefits will they see? Quantified benefits, if possible! -- 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
