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
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");
+ }
+
if (mm) {
task_mem(m, mm);
task_core_dumping(m, task);
--
2.39.1
