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

From: Phil Auld
Date: Thu Aug 12 2021 - 11:47:12 EST


Hi,

On Thu, Aug 12, 2021 at 07:39:34PM +0530 Shirish S 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 ~ #

Thanks. Probably want to update this "father" too.

And as Steve said, maybe a line or 2 of actual data?

Cheers,
Phil

>
> 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..d9c7014870d5 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 ppid\n");
> +
> rcu_read_lock();
> for_each_process_thread(g, p) {
> /*
> --
> 2.17.1
>

--