Freeing a cpu for ftracing

1 files changed, 15 insertions, 4 deletions

diff --git a/litmus/sched_mc.c b/litmus/sched_mc.c
index 53c24ac2172c..8828919dfcf2 100644
--- a/litmus/sched_mc.c
+++ b/litmus/sched_mc.c
@@ -60,6 +60,8 @@ DEFINE_PER_CPU(struct cpu_entry, cpus);
 static int interrupt_cpu;
 #endif
 
+struct cpumask rt_mask;
+
 #define domain_data(dom)  (container_of(dom, struct domain_data, domain))
 #define is_global(dom)    (domain_data(dom)->heap)
 #define is_global_task(t) (is_global(get_task_domain(t)))
@@ -350,7 +352,7 @@ static void fix_global_levels(void)
         struct task_struct *t;
 
         STRACE("Fixing global levels\n");
-        for_each_online_cpu(c) {
+        for_each_rt_cpu(c) {
                 e = &per_cpu(cpus, c);
                 raw_spin_lock(&e->redir_lock);
                 list_for_each_safe(pos, safe, &e->redir) {
@@ -377,6 +379,7 @@ static void link_task_to_cpu(struct cpu_entry *entry, struct task_struct *task)
         TRACE_MC_TASK(task, "Linking to P%d\n", entry->cpu);
         BUG_ON(task && tsk_rt(task)->linked_on != entry->cpu);
         BUG_ON(task && is_ghost(task));
+        BUG_ON(CONFIG_FTRACE_CPU == entry->cpu);
 
         if (task){
                 set_rt_flags(task, RT_F_RUNNING);
@@ -892,6 +895,10 @@ static struct task_struct* mc_schedule(struct task_struct* prev)
         int i, out_of_time, sleep, preempt, exists, blocks, global, lower;
         struct task_struct *dtask = NULL, *ready_task = NULL, *next = NULL;
 
+        /* Give FTRACE a CPU to run on */
+        if (CONFIG_FTRACE_CPU == entry->cpu)
+                return NULL;
+
         local_irq_save(flags);
 
         /* Litmus gave up because it couldn't access the stack of the CPU
@@ -1075,7 +1082,7 @@ static long mc_activate_plugin(void)
 #endif
 #endif
 
-        for_each_online_cpu(cpu) {
+        for_each_rt_cpu(cpu) {
                 BUG_ON(NR_CPUS <= n);
                 dom = per_cpu(cpus, cpu).crit_entries[CRIT_LEVEL_A].domain;
                 dom_data = domain_data(dom);
@@ -1150,7 +1157,7 @@ static void init_global_domain(struct domain_data *dom_data, enum crit_level lev
         dom_data->heap = heap;
         bheap_init(heap);
 
-        for_each_online_cpu(cpu) {
+        for_each_rt_cpu(cpu) {
                 entry = &per_cpu(cpus, cpu);
                 node = &nodes[cpu];
                 ce = &entry->crit_entries[level];
@@ -1199,7 +1206,11 @@ static int __init init_mc(void)
         raw_spinlock_t *a_dom_lock, *b_dom_lock, *c_dom_lock; /* For lock debugger */
         struct ce_dom_data *ce_data;
 
-        for_each_online_cpu(cpu) {
+#if CONFIG_FTRACE_CPU != NO_CPU
+        cpumask_xor(&rt_mask, cpu_online_mask, cpumask_of(CONFIG_FTRACE_CPU));
+#endif
+
+        for_each_rt_cpu(cpu) {
                 entry = &per_cpu(cpus, cpu);
 
                 /* CPU */