diff --git a/zion/debug/debug.h b/zion/debug/debug.h
index 567bf79..ed07d9a 100644
--- a/zion/debug/debug.h
+++ b/zion/debug/debug.h
@@ -28,6 +28,12 @@ void panic(const char* str, Args... args) {
   asm volatile("cli; hlt;");
 }
 
+#define PANIC_ON_ERR(expr, str) \
+  {                             \
+    if (expr != glcr::OK) {     \
+      panic(str);               \
+    }                           \
+  }
 #define UNREACHABLE                                \
   panic("Unreachable {}, {}", __FILE__, __LINE__); \
   __builtin_unreachable();
diff --git a/zion/scheduler/process_manager.cpp b/zion/scheduler/process_manager.cpp
index 3291a81..1390615 100644
--- a/zion/scheduler/process_manager.cpp
+++ b/zion/scheduler/process_manager.cpp
@@ -10,19 +10,12 @@ void ProcessManager::Init() {
 }
 
 void ProcessManager::InsertProcess(const glcr::RefPtr<Process>& proc) {
-  proc_list_.PushBack(proc);
+  PANIC_ON_ERR(proc_map_.Insert(proc->id(), proc), "Reinserting process");
 }
 
 Process& ProcessManager::FromId(uint64_t pid) {
-  if (pid >= proc_list_.size()) {
-    panic("Bad proc access {}, have {} processes", pid, proc_list_.size());
-  }
-  return *proc_list_[pid];
-}
-
-void ProcessManager::DumpProcessStates() {
-  dbgln("Process States: {}", proc_list_.size());
-  for (uint64_t i = 0; i < proc_list_.size(); i++) {
-    dbgln("{}: {}", proc_list_[i]->id(), (uint64_t)proc_list_[i]->GetState());
+  if (!proc_map_.Contains(pid)) {
+    panic("Bad proc access {}, have {} processes", pid, proc_map_.size());
   }
+  return *proc_map_.at(pid);
 }
diff --git a/zion/scheduler/process_manager.h b/zion/scheduler/process_manager.h
index 509ecd3..9efbaa9 100644
--- a/zion/scheduler/process_manager.h
+++ b/zion/scheduler/process_manager.h
@@ -14,11 +14,8 @@ class ProcessManager {
   void InsertProcess(const glcr::RefPtr<Process>& proc);
   Process& FromId(uint64_t id);
 
-  void DumpProcessStates();
-
  private:
-  // TODO: This should be a hashmap.
-  glcr::Vector<glcr::RefPtr<Process>> proc_list_;
+  glcr::HashMap<uint64_t, glcr::RefPtr<Process>> proc_map_;
 };
 
 extern ProcessManager* gProcMan;