On Wed, Apr 12, 2023 at 02:12:16PM -0700, Andrew Morton wrote: > On Wed, 12 Apr 2023 22:34:02 +0800 Chunguang Wu <aman2008@xxxxxx> wrote: > > > user can know that a process is kernel thread or not. > > > > ... > > > > --- a/fs/proc/array.c > > +++ b/fs/proc/array.c > > @@ -434,6 +434,12 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns, > > > > task_state(m, ns, pid, task); > > > > + if ((mm == NULL) || (task->flags & PF_KTHREAD)) { > > + seq_puts(m, "Kthread:\tYes\n"); > > + } else { > > + seq_puts(m, "Kthread:\tNo\n"); > > + } "mm" check is redundant. PF_KTHREAD should be enough. If you're doing this, just print 0/1. > > if (mm) { > > task_mem(m, mm); > > task_core_dumping(m, task); > > Well.. Why is this information useful? I want to add: for a shell script. Real programs can read /proc/*/stat . > What is the use case? > > There are many ways of working this out from the existing output - why > is this change required?