pidns: make pid->level and pid_ns->level unsigned

These values represent the nesting level of a namespace and pids living in it,
and it's always non-negative.

Turning this from int to unsigned int saves some space in pid.c (11 bytes on
x86 and 64 on ia64) by letting the compiler optimize the pid_nr_ns a bit.
E.g.  on ia64 this removes the sign extension calls, which compiler adds to
optimize access to pid->nubers[ns->level].

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 3 insertions, 3 deletions

diff --git a/include/linux/pid.h b/include/linux/pid.h
index 8d199033c0ca..c21c7e8124a7 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -60,7 +60,7 @@ struct pid
         /* lists of tasks that use this pid */
         struct hlist_head tasks[PIDTYPE_MAX];
         struct rcu_head rcu;
-        int level;
+        unsigned int level;
         struct upid numbers[1];
 };
 
diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h
index fcd61fa2c833..caff5283d15c 100644
--- a/include/linux/pid_namespace.h
+++ b/include/linux/pid_namespace.h
@@ -20,7 +20,7 @@ struct pid_namespace {
         int last_pid;
         struct task_struct *child_reaper;
         struct kmem_cache *pid_cachep;
-        int level;
+        unsigned int level;
         struct pid_namespace *parent;
 #ifdef CONFIG_PROC_FS
         struct vfsmount *proc_mnt;
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 5ca37fa50beb..98702b4b8851 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -66,7 +66,7 @@ err_alloc:
         return NULL;
 }
 
-static struct pid_namespace *create_pid_namespace(int level)
+static struct pid_namespace *create_pid_namespace(unsigned int level)
 {
         struct pid_namespace *ns;
         int i;