Remove option for threading of all softirqs.wip-gpu-interrupts

2 files changed, 52 insertions, 106 deletions

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
diff --git a/litmus/Kconfig b/litmus/Kconfig
index 158261e0ed08..478e82570bac 100644
--- a/litmus/Kconfig
+++ b/litmus/Kconfig
@@ -217,22 +217,6 @@ endmenu
 
 menu "Interrupt Handling"
 
-config LITMUS_THREAD_ALL_SOFTIRQ
-       bool "Process all softirqs in ksoftirqd threads."
-       default n
-       help
-             (Experimental) Thread all softirqs to ksoftirqd
-                 daemon threads, similar to PREEMPT_RT.  I/O
-                 throughput will will drop with this enabled, but
-                 latencies due to interrupts will be reduced.
-
-                 WARNING: Timer responsiveness will likely be
-                 decreased as timer callbacks are also threaded.
-                 This is unlike PREEEMPT_RTs hardirqs.
-
-                If unsure, say No.
-
-
 choice 
         prompt "Scheduling of interrupt bottom-halves in Litmus."
         default LITMUS_SOFTIRQD_NONE