* Re: [PATCH] fs/proc: add Kthread flag to /proc/$pid/status
[not found] <tencent_3E1CBD85D91AD4CDDCB5F429A3948EB94306@qq.com>
@ 2023-04-12 21:12 ` Andrew Morton
2023-04-13 18:36 ` Alexey Dobriyan
0 siblings, 1 reply; 6+ messages in thread
From: Andrew Morton @ 2023-04-12 21:12 UTC (permalink / raw)
To: Chunguang Wu; +Cc: linux-kernel, linux-fsdevel, Alexey Dobriyan
On Wed, 12 Apr 2023 22:34:02 +0800 Chunguang Wu <aman2008@qq.com> wrote:
> user can know that a process is kernel thread or not.
>
> ...
>
> --- a/fs/proc/array.c
> +++ b/fs/proc/array.c
> @@ -434,6 +434,12 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
>
> task_state(m, ns, pid, task);
>
> + if ((mm == NULL) || (task->flags & PF_KTHREAD)) {
> + seq_puts(m, "Kthread:\tYes\n");
> + } else {
> + seq_puts(m, "Kthread:\tNo\n");
> + }
> +
> if (mm) {
> task_mem(m, mm);
> task_core_dumping(m, task);
Well.. Why is this information useful? What is the use case?
There are many ways of working this out from the existing output - why
is this change required?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] fs/proc: add Kthread flag to /proc/$pid/status
2023-04-12 21:12 ` [PATCH] fs/proc: add Kthread flag to /proc/$pid/status Andrew Morton
@ 2023-04-13 18:36 ` Alexey Dobriyan
0 siblings, 0 replies; 6+ messages in thread
From: Alexey Dobriyan @ 2023-04-13 18:36 UTC (permalink / raw)
To: Andrew Morton; +Cc: Chunguang Wu, linux-kernel, linux-fsdevel
On Wed, Apr 12, 2023 at 02:12:16PM -0700, Andrew Morton wrote:
> On Wed, 12 Apr 2023 22:34:02 +0800 Chunguang Wu <aman2008@qq.com> wrote:
>
> > user can know that a process is kernel thread or not.
> >
> > ...
> >
> > --- a/fs/proc/array.c
> > +++ b/fs/proc/array.c
> > @@ -434,6 +434,12 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
> >
> > task_state(m, ns, pid, task);
> >
> > + if ((mm == NULL) || (task->flags & PF_KTHREAD)) {
> > + seq_puts(m, "Kthread:\tYes\n");
> > + } else {
> > + seq_puts(m, "Kthread:\tNo\n");
> > + }
"mm" check is redundant. PF_KTHREAD should be enough.
If you're doing this, just print 0/1.
> > if (mm) {
> > task_mem(m, mm);
> > task_core_dumping(m, task);
>
> Well.. Why is this information useful?
I want to add: for a shell script.
Real programs can read /proc/*/stat .
> What is the use case?
>
> There are many ways of working this out from the existing output - why
> is this change required?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] fs/proc: add Kthread flag to /proc/$pid/status
2023-04-15 8:21 Chunguang Wu
@ 2023-04-15 16:03 ` Randy Dunlap
0 siblings, 0 replies; 6+ messages in thread
From: Randy Dunlap @ 2023-04-15 16:03 UTC (permalink / raw)
To: Chunguang Wu, akpm, corbet
Cc: adobriyan, linux-kernel, linux-fsdevel, linux-doc
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/$pid/status`.
>
> Signed-off-by: Chunguang Wu <fullspring2018@gmail.com>
> ---
> Documentation/filesystems/proc.rst | 2 ++
> fs/proc/array.c | 7 +++++++
> 2 files changed, 9 insertions(+)
>
> diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
> index 9d5fd9424e8b..8a563684586c 100644
> --- a/Documentation/filesystems/proc.rst
> +++ b/Documentation/filesystems/proc.rst
> @@ -179,6 +179,7 @@ read the file /proc/PID/status::
> Gid: 100 100 100 100
> FDSize: 256
> Groups: 100 14 16
> + Kthread: 0
> VmPeak: 5004 kB
> VmSize: 5004 kB
> VmLck: 0 kB
> @@ -256,6 +257,7 @@ It's slow but very precise.
> NSpid descendant namespace process ID hierarchy
> NSpgid descendant namespace process group ID hierarchy
> NSsid descendant namespace session ID hierarchy
> + Kthread kernel thread flag, 1 is yes, 0 is no
> VmPeak peak virtual memory size
> VmSize total program size
> VmLck locked memory size
The Documentation changes look good, except that they may need to be moved
if you do the changes indicated below.
Now that I have looked at the rest of the patch:
> diff --git a/fs/proc/array.c b/fs/proc/array.c
> index 9b0315d34c58..fde6a0b92728 100644
> --- a/fs/proc/array.c
> +++ b/fs/proc/array.c
> @@ -434,6 +434,13 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
>
> task_state(m, ns, pid, task);
>
> + seq_puts(m, "Kthread:\t");
> + if (task->flags & PF_KTHREAD) {
> + seq_puts(m, "1\n");
> + } else {
> + seq_puts(m, "0\n");
> + }
> +
I would put that patch fragment inside task_state(), but I'll leave that
to others to decide on.
and condense it to one line, e.g.:
seq_puts(m, "Kthread: %c\n", task->flags & PF_KTHREAD ? '1' : '0');
> if (mm) {
> task_mem(m, mm);
> task_core_dumping(m, task);
Please add version info to your future patches.
Thanks.
--
~Randy
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] fs/proc: add Kthread flag to /proc/$pid/status
@ 2023-04-15 8:21 Chunguang Wu
2023-04-15 16:03 ` Randy Dunlap
0 siblings, 1 reply; 6+ messages in thread
From: Chunguang Wu @ 2023-04-15 8:21 UTC (permalink / raw)
To: akpm, corbet; +Cc: adobriyan, rdunlap, linux-kernel, linux-fsdevel, linux-doc
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/$pid/status`.
Signed-off-by: Chunguang Wu <fullspring2018@gmail.com>
---
Documentation/filesystems/proc.rst | 2 ++
fs/proc/array.c | 7 +++++++
2 files changed, 9 insertions(+)
diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index 9d5fd9424e8b..8a563684586c 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -179,6 +179,7 @@ read the file /proc/PID/status::
Gid: 100 100 100 100
FDSize: 256
Groups: 100 14 16
+ Kthread: 0
VmPeak: 5004 kB
VmSize: 5004 kB
VmLck: 0 kB
@@ -256,6 +257,7 @@ It's slow but very precise.
NSpid descendant namespace process ID hierarchy
NSpgid descendant namespace process group ID hierarchy
NSsid descendant namespace session ID hierarchy
+ Kthread kernel thread flag, 1 is yes, 0 is no
VmPeak peak virtual memory size
VmSize total program size
VmLck locked memory size
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 9b0315d34c58..fde6a0b92728 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -434,6 +434,13 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
task_state(m, ns, pid, task);
+ seq_puts(m, "Kthread:\t");
+ if (task->flags & PF_KTHREAD) {
+ seq_puts(m, "1\n");
+ } else {
+ seq_puts(m, "0\n");
+ }
+
if (mm) {
task_mem(m, mm);
task_core_dumping(m, task);
--
2.39.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] fs/proc: add Kthread flag to /proc/$pid/status
2023-04-14 9:27 Chunguang Wu
@ 2023-04-14 15:17 ` Randy Dunlap
0 siblings, 0 replies; 6+ messages in thread
From: Randy Dunlap @ 2023-04-14 15:17 UTC (permalink / raw)
To: Chunguang Wu, akpm; +Cc: adobriyan, linux-kernel, linux-fsdevel
Hi--
On 4/14/23 02:27, 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/$pid/status`.
>
Please update Documentation/filesystems/proc.rst:
(1) the example:
For example, to get the status information of a process, all you have to do is
read the file /proc/PID/status::
and (2): table 1-2
Thanks.
> Signed-off-by: Chunguang Wu <fullspring2018@gmail.com>
> ---
> fs/proc/array.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/fs/proc/array.c b/fs/proc/array.c
> index 9b0315d34c58..fde6a0b92728 100644
> --- a/fs/proc/array.c
> +++ b/fs/proc/array.c
> @@ -434,6 +434,13 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
>
> task_state(m, ns, pid, task);
>
> + seq_puts(m, "Kthread:\t");
> + if (task->flags & PF_KTHREAD) {
> + seq_puts(m, "1\n");
> + } else {
> + seq_puts(m, "0\n");
> + }
> +
> if (mm) {
> task_mem(m, mm);
> task_core_dumping(m, task);
--
~Randy
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] fs/proc: add Kthread flag to /proc/$pid/status
@ 2023-04-14 9:27 Chunguang Wu
2023-04-14 15:17 ` Randy Dunlap
0 siblings, 1 reply; 6+ messages in thread
From: Chunguang Wu @ 2023-04-14 9:27 UTC (permalink / raw)
To: akpm; +Cc: adobriyan, linux-kernel, linux-fsdevel
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/$pid/status`.
Signed-off-by: Chunguang Wu <fullspring2018@gmail.com>
---
fs/proc/array.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 9b0315d34c58..fde6a0b92728 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -434,6 +434,13 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
task_state(m, ns, pid, task);
+ seq_puts(m, "Kthread:\t");
+ if (task->flags & PF_KTHREAD) {
+ seq_puts(m, "1\n");
+ } else {
+ seq_puts(m, "0\n");
+ }
+
if (mm) {
task_mem(m, mm);
task_core_dumping(m, task);
--
2.39.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-04-15 16:03 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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[not found] <tencent_3E1CBD85D91AD4CDDCB5F429A3948EB94306@qq.com>
2023-04-12 21:12 ` [PATCH] fs/proc: add Kthread flag to /proc/$pid/status Andrew Morton
2023-04-13 18:36 ` Alexey Dobriyan
2023-04-14 9:27 Chunguang Wu
2023-04-14 15:17 ` Randy Dunlap
2023-04-15 8:21 Chunguang Wu
2023-04-15 16:03 ` Randy Dunlap
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