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 | 2 ++ 2 files changed, 4 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 diff --git a/fs/proc/array.c b/fs/proc/array.c index 9b0315d34c58..425824ad85e1 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -219,6 +219,8 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, seq_put_decimal_ull(m, "\t", task_session_nr_ns(p, pid->numbers[g].ns)); #endif seq_putc(m, '\n'); + + seq_printf(m, "Kthread:\t%c\n", p->flags & PF_KTHREAD ? '1' : '0'); } void render_sigset_t(struct seq_file *m, const char *header, -- 2.39.1
