path: root/kernel/pid.c
diff options
authorEric W. Biederman <>2010-03-02 14:51:53 -0800
committerEric W. Biederman <>2012-11-19 05:59:09 -0800
commit17cf22c33e1f1b5e435469c84e43872579497653 (patch)
treec5cec307c06f7e4ddc26e04e73c8833897b67113 /kernel/pid.c
parent49f4d8b93ccf9454284b6f524b96c66d8d7fbccc (diff)
pidns: Use task_active_pid_ns where appropriate
The expressions tsk->nsproxy->pid_ns and task_active_pid_ns aka ns_of_pid(task_pid(tsk)) should have the same number of cache line misses with the practical difference that ns_of_pid(task_pid(tsk)) is released later in a processes life. Furthermore by using task_active_pid_ns it becomes trivial to write an unshare implementation for the the pid namespace. So I have used task_active_pid_ns everywhere I can. In fork since the pid has not yet been attached to the process I use ns_of_pid, to achieve the same effect. Signed-off-by: Eric W. Biederman <>
Diffstat (limited to 'kernel/pid.c')
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/pid.c b/kernel/pid.c
index 2a624f1486e1..3a5f238c1ca0 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -345,7 +345,7 @@ EXPORT_SYMBOL_GPL(find_pid_ns);
struct pid *find_vpid(int nr)
- return find_pid_ns(nr, current->nsproxy->pid_ns);
+ return find_pid_ns(nr, task_active_pid_ns(current));
@@ -429,7 +429,7 @@ struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns)
struct task_struct *find_task_by_vpid(pid_t vnr)
- return find_task_by_pid_ns(vnr, current->nsproxy->pid_ns);
+ return find_task_by_pid_ns(vnr, task_active_pid_ns(current));
struct pid *get_task_pid(struct task_struct *task, enum pid_type type)
@@ -484,7 +484,7 @@ EXPORT_SYMBOL_GPL(pid_nr_ns);
pid_t pid_vnr(struct pid *pid)
- return pid_nr_ns(pid, current->nsproxy->pid_ns);
+ return pid_nr_ns(pid, task_active_pid_ns(current));
@@ -495,7 +495,7 @@ pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
if (!ns)
- ns = current->nsproxy->pid_ns;
+ ns = task_active_pid_ns(current);
if (likely(pid_alive(task))) {
if (type != PIDTYPE_PID)
task = task->group_leader;