Try reverting the softirq handling to see if it's better or worse without it.

-ck

diff --git a/kernel/sched/MuQSS.c b/kernel/sched/MuQSS.c
index 2fa9683..987f288 100644
--- a/kernel/sched/MuQSS.c
+++ b/kernel/sched/MuQSS.c
@@ -752,13 +752,6 @@ static inline bool task_queued(struct task_struct *p)
 static void enqueue_task(struct rq *rq, struct task_struct *p, int flags);
 static inline void resched_if_idle(struct rq *rq);
 
-/* Dodgy workaround till we figure out where the softirqs are going */
-static inline void do_pending_softirq(struct rq *rq, struct task_struct *next)
-{
-	if (unlikely(next == rq->idle && local_softirq_pending() && !in_interrupt()))
-		do_softirq_own_stack();
-}
-
 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
 {
 #ifdef CONFIG_SMP
@@ -813,11 +806,7 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
 		raw_spin_unlock(&prev->pi_lock);
 	}
 #endif
-	rq_unlock(rq);
-
-	do_pending_softirq(rq, current);
-
-	local_irq_enable();
+	rq_unlock_irq(rq);
 }
 
 static inline bool deadline_before(u64 deadline, u64 time)
@@ -3857,9 +3846,7 @@ static void __sched notrace __schedule(bool preempt)
 		context_switch(rq, prev, next); /* unlocks the rq */
 	} else {
 		check_siblings(rq);
-		rq_unlock(rq);
-		do_pending_softirq(rq, next);
-		local_irq_enable();
+		rq_unlock_irq(rq);
 	}
 }
 
diff --git a/kernel/sched/MuQSS.h b/kernel/sched/MuQSS.h
index 3565a7d..f9510d7 100644
--- a/kernel/sched/MuQSS.h
+++ b/kernel/sched/MuQSS.h
@@ -1,6 +1,5 @@
 #include <linux/sched.h>
 #include <linux/cpuidle.h>
-#include <linux/interrupt.h>
 #include <linux/skip_list.h>
 #include <linux/stop_machine.h>
 #include "cpuacct.h"
@@ -326,18 +325,4 @@ static inline void cpufreq_trigger(u64 time, unsigned long util)
 #define arch_scale_freq_invariant()	(false)
 #endif
 
-/*
- * This should only be called when current == rq->idle. Dodgy workaround for
- * when softirqs are pending and we are in the idle loop. Setting current to
- * resched will kick us out of the idle loop and the softirqs will be serviced
- * on our next pass through schedule().
- */
-static inline bool softirq_pending(int cpu)
-{
-	if (likely(!local_softirq_pending()))
-		return false;
-	set_tsk_need_resched(current);
-	return true;
-}
-
 #endif /* MUQSS_SCHED_H */
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index 51264e6..060b76d 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -208,8 +208,6 @@ static void cpu_idle_loop(void)
 	int cpu = smp_processor_id();
 
 	while (1) {
-		bool pending = false;
-
 		/*
 		 * If the arch has a polling bit, we maintain an invariant:
 		 *
@@ -221,10 +219,7 @@ static void cpu_idle_loop(void)
 
 		__current_set_polling();
 		quiet_vmstat();
-		if (unlikely(softirq_pending(cpu)))
-			pending = true;
-		else
-			tick_nohz_idle_enter();
+		tick_nohz_idle_enter();
 
 		while (!need_resched()) {
 			check_pgt_cache();
@@ -264,8 +259,7 @@ static void cpu_idle_loop(void)
 		 * not have had an IPI to fold the state for us.
 		 */
 		preempt_set_need_resched();
-		if (!pending)
-			tick_nohz_idle_exit();
+		tick_nohz_idle_exit();
 		__current_clr_polling();
 
 		/*
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index cdefab6..c64fc51 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1813,8 +1813,3 @@ static inline void cpufreq_trigger_update(u64 time) {}
 #else /* arch_scale_freq_capacity */
 #define arch_scale_freq_invariant()	(false)
 #endif
-
-static inline bool softirq_pending(int cpu)
-{
-	return false;
-}