On Mon, Nov 28, 2016 at 10:33 PM, Jacob Pan <jacob.jun....@linux.intel.com> wrote: > From: Peter Zijlstra <pet...@infradead.org> > > Idle injection drivers such as Intel powerclamp and ACPI PAD drivers use > realtime tasks to take control of CPU then inject idle. There are two > issues with this approach: > > 1. Low efficiency: injected idle task is treated as busy so sched ticks > do not stop during injected idle period, the result of these > unwanted wakeups can be ~20% loss in power savings. > > 2. Idle accounting: injected idle time is presented to user as busy. > > This patch addresses the issues by introducing a new PF_IDLE flag which > allows any given task to be treated as idle task while the flag is set. > Therefore, idle injection tasks can run through the normal flow of NOHZ > idle enter/exit to get the correct accounting as well as tick stop when > possible. > > The implication is that idle task is then no longer limited to PID == 0. > > Acked-by: Ingo Molnar <mi...@kernel.org> > Signed-off-by: Peter Zijlstra <pet...@infradead.org> > Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com>
Have you made any changes to the original Peter's patch, or is this just a resend of that? Thanks, Rafael
