From adeff95dcdcf88789e983f20b0657f29286de8d7 Mon Sep 17 00:00:00 2001
From: Glenn Elliott <gelliott@cs.unc.edu>
Date: Mon, 5 Mar 2012 14:59:07 -0500
Subject: Remove option for threading of all softirqs.

---
 kernel/softirq.c | 142 ++++++++++++++++++++-----------------------------------
 1 file changed, 52 insertions(+), 90 deletions(-)

(limited to 'kernel')

diff --git a/kernel/softirq.c b/kernel/softirq.c
index 48d6bde692a1..7c562558a863 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -214,105 +214,67 @@ EXPORT_SYMBOL(local_bh_enable_ip);
  */
 #define MAX_SOFTIRQ_RESTART 10
 
-static void ____do_softirq(void)
+asmlinkage void __do_softirq(void)
 {
-	__u32 pending;
-	
-	struct softirq_action *h;
-	int cpu;
-	
-	pending = local_softirq_pending();
-	
-	account_system_vtime(current);
+    struct softirq_action *h; 
+    __u32 pending;
+    int max_restart = MAX_SOFTIRQ_RESTART;
+    int cpu;
 
-	__local_bh_disable((unsigned long)__builtin_return_address(0),
-				SOFTIRQ_OFFSET);
-	lockdep_softirq_enter();
+    pending = local_softirq_pending();
+    account_system_vtime(current);
 
-	cpu = smp_processor_id();
+    __local_bh_disable((unsigned long)__builtin_return_address(0),
+                SOFTIRQ_OFFSET);
+    lockdep_softirq_enter();
 
-	set_softirq_pending(0);
-	
-	local_irq_enable();
-	
-	h = softirq_vec;
-	
-	do {
-		if (pending & 1) {
-			unsigned int vec_nr = h - softirq_vec;
-			int prev_count = preempt_count();
-
-			kstat_incr_softirqs_this_cpu(vec_nr);
-
-			trace_softirq_entry(vec_nr);
-			h->action(h);
-			trace_softirq_exit(vec_nr);
-			if (unlikely(prev_count != preempt_count())) {
-				printk(KERN_ERR "huh, entered softirq %u %s %p"
-				       "with preempt_count %08x,"
-				       " exited with %08x?\n", vec_nr,
-				       softirq_to_name[vec_nr], h->action,
-				       prev_count, preempt_count());
-				preempt_count() = prev_count;
-			}
-			
-			rcu_bh_qs(cpu);
-		}
-		h++;
-		pending >>= 1;
-	} while (pending);
-	
-	local_irq_disable();
-}
+    cpu = smp_processor_id();
+restart:
+    /* Reset the pending bitmask before enabling irqs */
+    set_softirq_pending(0);
 
-static void ___do_softirq(void)
-{
-	int max_restart = MAX_SOFTIRQ_RESTART;
-	__u32 pending;
+    local_irq_enable();
 
-restart:
-	____do_softirq();
+    h = softirq_vec;
 
-	pending = local_softirq_pending();
-	if (pending && --max_restart)
-		goto restart;
+    do {
+        if (pending & 1) {
+            unsigned int vec_nr = h - softirq_vec;
+            int prev_count = preempt_count();
 
-	if (pending)
-		wakeup_softirqd();
-}
+            kstat_incr_softirqs_this_cpu(vec_nr);
 
-asmlinkage void __do_softirq(void)
-{
-#ifdef LITMUS_THREAD_ALL_SOFTIRQ
-	/* Skip straight to wakeup_softirqd() if we're using 
-	 LITMUS_THREAD_ALL_SOFTIRQ (unless there's really high prio-stuff waiting.). */
-	struct task_struct *tsk = __get_cpu_var(ksoftirqd);
-	
-	if(tsk)
-	{
-		__u32 pending = local_softirq_pending();
-		const __u32 high_prio_softirq = (1<<HI_SOFTIRQ) | (1<<TIMER_SOFTIRQ) | (1<<HRTIMER_SOFTIRQ);
-		if(pending && !(pending & high_prio_softirq))
-		{
-			wakeup_softirqd();
-			return;
-		}
-	}
-#endif
-	
-	/*
-	 * 'immediate' softirq execution:
-	 */
-	__local_bh_disable((unsigned long)__builtin_return_address(0),
-			SOFTIRQ_OFFSET);
-	lockdep_softirq_enter();
-	
-	___do_softirq();
-	
-	lockdep_softirq_exit();
-	
-	account_system_vtime(current);
-	__local_bh_enable(SOFTIRQ_OFFSET);
+            trace_softirq_entry(vec_nr);
+            h->action(h);
+            trace_softirq_exit(vec_nr);
+            if (unlikely(prev_count != preempt_count())) {
+                printk(KERN_ERR "huh, entered softirq %u %s %p"
+                       "with preempt_count %08x,"
+                       " exited with %08x?\n", vec_nr,
+                       softirq_to_name[vec_nr], h->action,
+                       prev_count, preempt_count());
+                preempt_count() = prev_count;
+            }   
+
+            rcu_bh_qs(cpu);
+        }   
+        h++;
+        pending >>= 1;
+    } while (pending);
+
+    local_irq_disable();
+
+    pending = local_softirq_pending();
+    if (pending && --max_restart)
+        goto restart;
+
+    if (pending)
+        wakeup_softirqd();
+
+    lockdep_softirq_exit();
+
+    account_system_vtime(current);
+    __local_bh_enable(SOFTIRQ_OFFSET);
 }
 
 #ifndef __ARCH_HAS_DO_SOFTIRQ
-- 
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