Re: [PATCH 11/12] pid: rewrite task helper functions avoiding task->pid and task->tgid

On Thu, Aug 22, 2013 at 10:05:55PM +0200, Peter Zijlstra wrote: > On Tue, Aug 20, 2013 at 05:32:03PM -0400, Richard Guy Briggs wrote: > > This stops these four task helper functions from using the deprecated and > > error-prone task->pid and task->tgid. > > > > (informed by ebiederman's ea5a4d01) > > Cc: "Eric W. Biederman" <ebiederm(a)xmission.com&gt; > > Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; > > --- > > include/linux/sched.h | 8 ++++---- > > 1 files changed, 4 insertions(+), 4 deletions(-) > > > > diff --git a/include/linux/sched.h b/include/linux/sched.h > > index 8e69807..46e739d 100644 > > --- a/include/linux/sched.h > > +++ b/include/linux/sched.h > > @@ -1579,7 +1579,7 @@ static inline int pid_alive(struct task_struct *p) > > */ > > static inline int is_global_init(struct task_struct *tsk) > > { > > - return tsk->pid == 1; > > + return task_pid_nr(tsk) == 1; > > } > > > > extern struct pid *cad_pid; > > @@ -1930,7 +1930,7 @@ extern struct task_struct *idle_task(int cpu); > > */ > > static inline bool is_idle_task(const struct task_struct *p) > > { > > - return p->pid == 0; > > + return task_pid(p) == &init_struct_pid; > > } > > extern struct task_struct *curr_task(int cpu); > > extern void set_curr_task(int cpu, struct task_struct *p); > > Why would you ever want to do this? It just makes these tests more > expensive for no gain what so ff'ing ever. Backups are generally considered a good idea, but in this case, I'd quote: "A man with one watch knows what time it is. A man with two is never certain."