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

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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>
This commit is contained in:
Pavel Emelyanov
2008-04-30 00:54:31 -07:00
committed by Linus Torvalds
parent ab883af53e
commit caafa43243
3 changed files with 3 additions and 3 deletions
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2
include/linux/pid.h
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@@ -60,7 +60,7 @@ struct pid
/* lists of tasks that use this pid */ /* lists of tasks that use this pid */
struct hlist_head tasks[PIDTYPE_MAX]; struct hlist_head tasks[PIDTYPE_MAX];
struct rcu_head rcu; struct rcu_head rcu;
int level; unsigned int level;
struct upid numbers[1]; struct upid numbers[1];
}; };

2
include/linux/pid_namespace.h
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@@ -20,7 +20,7 @@ struct pid_namespace {
int last_pid; int last_pid;
struct task_struct *child_reaper; struct task_struct *child_reaper;
struct kmem_cache *pid_cachep; struct kmem_cache *pid_cachep;
int level; unsigned int level;
struct pid_namespace *parent; struct pid_namespace *parent;
#ifdef CONFIG_PROC_FS #ifdef CONFIG_PROC_FS
struct vfsmount *proc_mnt; struct vfsmount *proc_mnt;

2
kernel/pid_namespace.c
View File

@@ -66,7 +66,7 @@ err_alloc:
return NULL; 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; struct pid_namespace *ns;
int i; int i;