diff --git a/arch/um/kernel/smp.c b/arch/um/kernel/smp.c
index c8d8d0a..511116a 100644
--- a/arch/um/kernel/smp.c
+++ b/arch/um/kernel/smp.c
@@ -143,7 +143,6 @@
 		idle = idle_thread(cpu);
 
 		init_idle(idle, cpu);
-		unhash_process(idle);
 
 		waittime = 200000000;
 		while (waittime-- && !cpu_isset(cpu, cpu_callin_map))
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 1f16fb1..ddc0df7 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1214,8 +1214,6 @@
 #define delay_group_leader(p) \
 		(thread_group_leader(p) && !thread_group_empty(p))
 
-extern void unhash_process(struct task_struct *p);
-
 /*
  * Protects ->fs, ->files, ->mm, ->ptrace, ->group_info, ->comm, keyring
  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
diff --git a/kernel/exit.c b/kernel/exit.c
index f436a6b..a94e1c3 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -56,8 +56,7 @@
 		detach_pid(p, PIDTYPE_SID);
 
 		list_del_init(&p->tasks);
-		if (p->pid)
-			__get_cpu_var(process_counts)--;
+		__get_cpu_var(process_counts)--;
 	}
 
 	remove_parent(p);
@@ -118,21 +117,6 @@
 		goto repeat;
 }
 
-/* we are using it only for SMP init */
-
-void unhash_process(struct task_struct *p)
-{
-	struct dentry *proc_dentry;
-
-	spin_lock(&p->proc_lock);
-	proc_dentry = proc_pid_unhash(p);
-	write_lock_irq(&tasklist_lock);
-	__unhash_process(p);
-	write_unlock_irq(&tasklist_lock);
-	spin_unlock(&p->proc_lock);
-	proc_pid_flush(proc_dentry);
-}
-
 /*
  * This checks not only the pgrp, but falls back on the pid if no
  * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
diff --git a/kernel/fork.c b/kernel/fork.c
index 74c6762..0c32e28 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1181,25 +1181,26 @@
 	 */
 	p->ioprio = current->ioprio;
 
-	add_parent(p);
-	if (unlikely(p->ptrace & PT_PTRACED))
-		__ptrace_link(p, current->parent);
+	if (likely(p->pid)) {
+		add_parent(p);
+		if (unlikely(p->ptrace & PT_PTRACED))
+			__ptrace_link(p, current->parent);
 
-	if (thread_group_leader(p)) {
-		p->signal->tty = current->signal->tty;
-		p->signal->pgrp = process_group(current);
-		p->signal->session = current->signal->session;
-		attach_pid(p, PIDTYPE_PGID, process_group(p));
-		attach_pid(p, PIDTYPE_SID, p->signal->session);
+		if (thread_group_leader(p)) {
+			p->signal->tty = current->signal->tty;
+			p->signal->pgrp = process_group(current);
+			p->signal->session = current->signal->session;
+			attach_pid(p, PIDTYPE_PGID, process_group(p));
+			attach_pid(p, PIDTYPE_SID, p->signal->session);
 
-		list_add_tail(&p->tasks, &init_task.tasks);
-		if (p->pid)
+			list_add_tail(&p->tasks, &init_task.tasks);
 			__get_cpu_var(process_counts)++;
+		}
+		attach_pid(p, PIDTYPE_TGID, p->tgid);
+		attach_pid(p, PIDTYPE_PID, p->pid);
+		nr_threads++;
 	}
-	attach_pid(p, PIDTYPE_TGID, p->tgid);
-	attach_pid(p, PIDTYPE_PID, p->pid);
 
-	nr_threads++;
 	total_forks++;
 	spin_unlock(&current->sighand->siglock);
 	write_unlock_irq(&tasklist_lock);
@@ -1263,7 +1264,7 @@
 	if (!task)
 		return ERR_PTR(-ENOMEM);
 	init_idle(task, cpu);
-	unhash_process(task);
+
 	return task;
 }
 
diff --git a/kernel/pid.c b/kernel/pid.c
index 7781d99..a9f2dfd 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -247,16 +247,8 @@
 
 void __init pidmap_init(void)
 {
-	int i;
-
 	pidmap_array->page = (void *)get_zeroed_page(GFP_KERNEL);
+	/* Reserve PID 0. We never call free_pidmap(0) */
 	set_bit(0, pidmap_array->page);
 	atomic_dec(&pidmap_array->nr_free);
-
-	/*
-	 * Allocate PID 0, and hash it via all PID types:
-	 */
-
-	for (i = 0; i < PIDTYPE_MAX; i++)
-		attach_pid(current, i, 0);
 }