Hi,
On 4/15/23 01:21, Chunguang Wu wrote:
> The command `ps -ef ` and `top -c` mark kernel thread by '['
> and ']', but sometimes the result is not correct.
> The task->flags in /proc/$pid/stat is good, but we need remember
> the value of PF_KTHREAD is 0x00200000 and convert dec to hex.
> If we have no binary program and shell script which read
> /proc/$pid/stat, we can know it directly by
> `cat /proc/$pid/status`.
>
> Signed-off-by: Chunguang Wu <fullspring2018@xxxxxxxxx>
> ---
> Documentation/filesystems/proc.rst | 2 ++
> fs/proc/array.c | 7 +++++++
> 2 files changed, 9 insertions(+)
>
> diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
> index 9d5fd9424e8b..8a563684586c 100644
> --- a/Documentation/filesystems/proc.rst
> +++ b/Documentation/filesystems/proc.rst
> @@ -179,6 +179,7 @@ read the file /proc/PID/status::
> Gid: 100 100 100 100
> FDSize: 256
> Groups: 100 14 16
> + Kthread: 0
> VmPeak: 5004 kB
> VmSize: 5004 kB
> VmLck: 0 kB
> @@ -256,6 +257,7 @@ It's slow but very precise.
> NSpid descendant namespace process ID hierarchy
> NSpgid descendant namespace process group ID hierarchy
> NSsid descendant namespace session ID hierarchy
> + Kthread kernel thread flag, 1 is yes, 0 is no
> VmPeak peak virtual memory size
> VmSize total program size
> VmLck locked memory size
The Documentation changes look good, except that they may need to be moved
if you do the changes indicated below.
Now that I have looked at the rest of the patch:
> diff --git a/fs/proc/array.c b/fs/proc/array.c
> index 9b0315d34c58..fde6a0b92728 100644
> --- a/fs/proc/array.c
> +++ b/fs/proc/array.c
> @@ -434,6 +434,13 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
>
> task_state(m, ns, pid, task);
>
> + seq_puts(m, "Kthread:\t");
> + if (task->flags & PF_KTHREAD) {
> + seq_puts(m, "1\n");
> + } else {
> + seq_puts(m, "0\n");
> + }
> +
I would put that patch fragment inside task_state(), but I'll leave that
to others to decide on.
and condense it to one line, e.g.:
seq_puts(m, "Kthread: %c\n", task->flags & PF_KTHREAD ? '1' : '0');
> if (mm) {
> task_mem(m, mm);
> task_core_dumping(m, task);
Please add version info to your future patches.
Thanks.
--
~Randy
