Add PD^2 scheduler plugin

PFAIR: fix wrong memset()

PFAIR: don't arm timer for tardy tasks

If the system is overloaded, tasks may be tardy. In that case, do not
arm timers. Rather, add tardy tasks back into the ready queue right
away.

PFAIR: use sched_trace_last_suspension_as_completion()

PFAIR: use inferred_sporadic_job_release_at()

rebase fix: use new hrtimer API in PFAIR plugin

1 files changed, 13 insertions, 0 deletions

diff --git a/litmus/Kconfig b/litmus/Kconfig
index 5916db3973ca..9fc402e79cfd 100644
--- a/litmus/Kconfig
+++ b/litmus/Kconfig
@@ -12,6 +12,19 @@ config PLUGIN_CEDF
           On smaller platforms (e.g., ARM PB11MPCore), using C-EDF
           makes little sense since there aren't any shared caches.
 
+config PLUGIN_PFAIR
+        bool "PFAIR"
+        default y
+        help
+          Include the PFAIR plugin (i.e., the PD^2 scheduler) in the kernel.
+          The PFAIR plugin requires high resolution timers (for staggered
+          quanta) and also requires HZ_PERIODIC (i.e., periodic timer ticks
+          even if a processor is idle, as quanta could be missed otherwise).
+          Further, the PFAIR plugin uses the system tick and thus requires
+          HZ=1000 to achive reasonable granularity.
+
+          If unsure, say Yes.
+
 config RELEASE_MASTER
         bool "Release-master Support"
         depends on SMP