Merge branch 'timers/nohz-posix-timers-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/nohz

Pull posix cpu timers handling on full dynticks from Frederic Weisbecker.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 52 insertions, 0 deletions

diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 99c3f13dd478..f6a792ab4983 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -111,6 +111,7 @@ config NO_HZ_FULL
         select RCU_USER_QS
         select RCU_NOCB_CPU
         select CONTEXT_TRACKING_FORCE
+        select IRQ_WORK
         help
          Adaptively try to shutdown the tick whenever possible, even when
          the CPU is running tasks. Typically this requires running a single
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index a76e09044f9f..884a9f302a06 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -147,6 +147,57 @@ static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs)
 static cpumask_var_t nohz_full_mask;
 bool have_nohz_full_mask;
 
+/*
+ * Re-evaluate the need for the tick on the current CPU
+ * and restart it if necessary.
+ */
+static void tick_nohz_full_check(void)
+{
+        /*
+         * STUB for now, will be filled with the full tick stop/restart
+         * infrastructure patches
+         */
+}
+
+static void nohz_full_kick_work_func(struct irq_work *work)
+{
+        tick_nohz_full_check();
+}
+
+static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
+        .func = nohz_full_kick_work_func,
+};
+
+/*
+ * Kick the current CPU if it's full dynticks in order to force it to
+ * re-evaluate its dependency on the tick and restart it if necessary.
+ */
+void tick_nohz_full_kick(void)
+{
+        if (tick_nohz_full_cpu(smp_processor_id()))
+                irq_work_queue(&__get_cpu_var(nohz_full_kick_work));
+}
+
+static void nohz_full_kick_ipi(void *info)
+{
+        tick_nohz_full_check();
+}
+
+/*
+ * Kick all full dynticks CPUs in order to force these to re-evaluate
+ * their dependency on the tick and restart it if necessary.
+ */
+void tick_nohz_full_kick_all(void)
+{
+        if (!have_nohz_full_mask)
+                return;
+
+        preempt_disable();
+        smp_call_function_many(nohz_full_mask,
+                               nohz_full_kick_ipi, NULL, false);
+        preempt_enable();
+}
+
 int tick_nohz_full_cpu(int cpu)
 {
         if (!have_nohz_full_mask)