Re: [PATCH] sched/debug: print column titles of show_state_filter()

From: Steven Rostedt
Date: Thu Aug 12 2021 - 10:38:59 EST


On Thu, 12 Aug 2021 16:35:34 +0530
Shirish S <shirish.s@xxxxxxx> wrote:

> This addition in the debug output shall improve readablitly..
> Its not intuitive for users that the pid printed in last column
> is of parent process.
>
> Without this patch:
> localhost ~ # dmesg -w &
> localhost ~ # echo w > /proc/sysrq-trigger
> [22148.730225] sysrq: Show Blocked State
> localhost ~ #
>
> With this patch:
> localhost ~ # dmesg -w &
> localhost ~ # echo w > /proc/sysrq-trigger
> [ 99.979365] sysrq: Show Blocked State
> --> [ 99.983471] task PC stack pid father
> localhost ~ #
>

It would had been more informative, if there were content to those lists.

Just a few lines would be good enough. But the above, just looks like
you are adding a useless header. :-/

In fact, I would argue that the title should not be displayed if the
content is empty.

Also, s/father/parent/ or s/father/ppid/

-- Steve



> v2: Dropped #ifdef logic
> v3: Sample output in commit message
>
> Signed-off-by: Shirish S <shirish.s@xxxxxxx>
> Suggested-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
> ---
> kernel/sched/core.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 20ffcc044134..1c7ea3ef5a9f 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -8174,6 +8174,9 @@ void show_state_filter(unsigned int state_filter)
> {
> struct task_struct *g, *p;
>
> + pr_info(" task%*s", BITS_PER_LONG == 32 ? 38 : 46,
> + "PC stack pid father\n");
> +
> rcu_read_lock();
> for_each_process_thread(g, p) {
> /*