Shrink task_struct if CONFIG_FUTEX=n

robust_list, compat_robust_list, pi_state_list, pi_state_cache are
really used if futexes are on.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 9 insertions, 3 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 87f2eb27ee10..57166582a3f5 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1132,13 +1132,14 @@ struct task_struct {
         int cpuset_mems_generation;
         int cpuset_mem_spread_rotor;
 #endif
+#ifdef CONFIG_FUTEX
         struct robust_list_head __user *robust_list;
 #ifdef CONFIG_COMPAT
         struct compat_robust_list_head __user *compat_robust_list;
 #endif
         struct list_head pi_state_list;
         struct futex_pi_state *pi_state_cache;
-
+#endif
         atomic_t fs_excl;       /* holding fs exclusive resources */
         struct rcu_head rcu;
 
diff --git a/kernel/exit.c b/kernel/exit.c
index 4c108df88a37..2c704c86edb3 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -947,12 +947,14 @@ fastcall NORET_TYPE void do_exit(long code)
                 exit_itimers(tsk->signal);
         }
         acct_collect(code, group_dead);
+#ifdef CONFIG_FUTEX
         if (unlikely(tsk->robust_list))
                 exit_robust_list(tsk);
-#if defined(CONFIG_FUTEX) && defined(CONFIG_COMPAT)
+#ifdef CONFIG_COMPAT
         if (unlikely(tsk->compat_robust_list))
                 compat_exit_robust_list(tsk);
 #endif
+#endif
         if (group_dead)
                 tty_audit_exit();
         if (unlikely(tsk->audit_context))
@@ -987,6 +989,7 @@ fastcall NORET_TYPE void do_exit(long code)
         mpol_free(tsk->mempolicy);
         tsk->mempolicy = NULL;
 #endif
+#ifdef CONFIG_FUTEX
         /*
          * This must happen late, after the PID is not
          * hashed anymore:
@@ -995,6 +998,7 @@ fastcall NORET_TYPE void do_exit(long code)
                 exit_pi_state_list(tsk);
         if (unlikely(current->pi_state_cache))
                 kfree(current->pi_state_cache);
+#endif
         /*
          * Make sure we are holding no locks:
          */
diff --git a/kernel/fork.c b/kernel/fork.c
index 8a97e92c604f..3e764f6f2be1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1156,13 +1156,14 @@ static struct task_struct *copy_process(unsigned long clone_flags,
          * Clear TID on mm_release()?
          */
         p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;
+#ifdef CONFIG_FUTEX
         p->robust_list = NULL;
 #ifdef CONFIG_COMPAT
         p->compat_robust_list = NULL;
 #endif
         INIT_LIST_HEAD(&p->pi_state_list);
         p->pi_state_cache = NULL;
-
+#endif
         /*
          * sigaltstack should be cleared when sharing the same VM
          */