Commit 522dc4e5 authored by Chunguang Wu's avatar Chunguang Wu Committed by Andrew Morton
Browse files

fs/proc: add Kthread flag to /proc/$pid/status 

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`.

Link: https://lkml.kernel.org/r/20230416052404.2920-1-fullspring2018@gmail.com


Signed-off-by: default avatarChunguang Wu <fullspring2018@gmail.com>
Reviewed-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 3647ebcf

Documentation/filesystems/proc.rst

+2 −0
Original line number Diff line number Diff line
@@ -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

fs/proc/array.c

+2 −0
Original line number Diff line number Diff line
@@ -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,