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Date:   Thu, 12 Aug 2021 10:04:00 -0400
From:   Phil Auld <pauld@redhat.com>
To:     Shirish S <shirish.s@amd.com>
Cc:     Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched/debug: print column titles of show_state_filter()
Message-ID: <YRUqUCB/DT3vFQQA@lorien.usersys.redhat.com>
References: <20210812110534.82349-1-shirish.s@amd.com>
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In-Reply-To: <20210812110534.82349-1-shirish.s@amd.com>
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Hi,

On Thu, Aug 12, 2021 at 04:35:34PM +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 ~ #
> 
> v2: Dropped #ifdef logic
> v3: Sample output in commit message
> 
> Signed-off-by: Shirish S <shirish.s@amd.com>
> Suggested-by: Steven Rostedt <rostedt@goodmis.org>
> ---
>  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");


"parent" or "ppid" please.


Cheers,
Phil

> +
>  	rcu_read_lock();
>  	for_each_process_thread(g, p) {
>  		/*
> -- 
> 2.17.1
> 

--