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| author | Pavel Emelyanov <xemul@openvz.org> | 2008-04-30 00:54:31 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-30 08:29:49 -0700 |
| commit | caafa4324335aeb11bc233d5f87aca8cce30beba (patch) | |
| tree | b6371b0c084ffb91f7304a7e392b28ccfdab8a2e | |
| parent | ab883af53ec1b87add43b32a28d8347f17d5155b (diff) | |
| download | lwn-caafa4324335aeb11bc233d5f87aca8cce30beba.tar.gz lwn-caafa4324335aeb11bc233d5f87aca8cce30beba.zip | |
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>
| -rw-r--r-- | include/linux/pid.h | 2 | ||||
| -rw-r--r-- | include/linux/pid_namespace.h | 2 | ||||
| -rw-r--r-- | kernel/pid_namespace.c | 2 |
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; |