Better proc_kill () and process cleanup

kernel/proc/proc.c

@@ -23,6 +23,12 @@
 #include <amd64/intr_defs.h>
 #endif
 
+/*
+ * Lock ordering:
+ * 1. proc_tree_lock
+ * 2. [cpu]->lock
+ */
+
 static struct rb_node_link* proc_tree = NULL;
 static spin_lock_t proc_tree_lock = SPIN_LOCK_INIT;
 
@@ -113,7 +119,6 @@ static void proc_register (struct proc* proc, struct cpu* cpu) {
   proc->cpu = cpu;
 
   spin_lock (&proc_tree_lock);
-
   spin_lock (&cpu->lock);
 
   rbtree_insert (struct proc, &cpu->proc_run_q, &proc->cpu_run_q_link, cpu_run_q_link, pid);
@@ -123,7 +128,6 @@ static void proc_register (struct proc* proc, struct cpu* cpu) {
     cpu->proc_current = proc;
 
   spin_unlock (&cpu->lock);
-
   spin_unlock (&proc_tree_lock);
 }
 
@@ -147,6 +151,10 @@ static struct proc* proc_find_sched (void) {
 
     rbtree_next (node, node);
 
+    if (!node) {
+      rbtree_first (&thiscpu->proc_run_q, node);
+    }
+
     if (node == first)
       break;
   }
@@ -159,7 +167,7 @@ void proc_sched (void) {
 
   spin_lock (&thiscpu->lock);
 
-  if (thiscpu->proc_run_q == NULL || thiscpu->proc_current == NULL) {
+  if (thiscpu->proc_run_q == NULL) {
     spin_unlock (&thiscpu->lock);
     goto idle;
   }
@@ -179,8 +187,25 @@ idle:
 }
 
 void proc_kill (struct proc* proc) {
-  /* mark for garbage collection */
   atomic_store (&proc->state, PROC_DEAD);
+
+  spin_lock (&proc_tree_lock);
+  rbtree_delete (&proc_tree, &proc->proc_tree_link);
+  spin_unlock (&proc_tree_lock);
+
+  struct cpu* cpu = proc->cpu;
+  spin_lock (&cpu->lock);
+  rbtree_delete (&cpu->proc_run_q, &proc->cpu_run_q_link);
+  spin_unlock (&cpu->lock);
+
+  DEBUG ("killed PID %d\n", proc->pid);
+
+  proc_cleanup (proc);
+
+  if (cpu == thiscpu)
+    proc_sched ();
+  else
+    cpu_request_sched (cpu);
 }
 
 static void proc_irq_sched (void* arg, void* regs) {
@@ -188,12 +213,18 @@ static void proc_irq_sched (void* arg, void* regs) {
   proc_sched ();
 }
 
+static void proc_irq_cpu_request_sched (void* arg, void* regs) {
+  (void)arg, (void)regs;
+  proc_sched ();
+}
+
 void proc_init (void) {
   struct proc* init = proc_spawn_rd ("init.exe");
   proc_register (init, thiscpu);
 
 #if defined(__x86_64__)
   irq_attach (&proc_irq_sched, NULL, SCHED_PREEMPT_TIMER, IRQ_INTERRUPT_SAFE);
+  irq_attach (&proc_irq_cpu_request_sched, NULL, CPU_REQUEST_SCHED, IRQ_INTERRUPT_SAFE);
 #endif
 
   do_sched (init);