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From:   zhouchuangao <zhouchuangao@vivo.com>
To:     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
Cc:     zhouchuangao <zhouchuangao@vivo.com>
Subject: [PATCH] kernel/sched/core: Print the time when the process entered the D state
Date:   Thu,  8 Jul 2021 22:05:59 -0700
Message-Id: <1625807160-112041-1-git-send-email-zhouchuangao@vivo.com>
Precedence: bulk

Sometimes we need to trigger /proc/sysrq-trigger to view the information
of the D state process in the system.
e.g:
echo w > /proc/sysrq-trigger

Here we print the scheduling time of the process, which is convenient
for us to judge the state of the system and for debugging.

Signed-off-by: zhouchuangao <zhouchuangao@vivo.com>
---
 kernel/sched/core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index cf16f8f..e03474d 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8154,9 +8154,10 @@ void sched_show_task(struct task_struct *p)
 	if (pid_alive(p))
 		ppid = task_pid_nr(rcu_dereference(p->real_parent));
 	rcu_read_unlock();
-	pr_cont(" stack:%5lu pid:%5d ppid:%6d flags:0x%08lx\n",
+	pr_cont(" stack:%5lu pid:%5d ppid:%6d flags:0x%08lx sched:%llu\n",
 		free, task_pid_nr(p), ppid,
-		(unsigned long)task_thread_info(p)->flags);
+		(unsigned long)task_thread_info(p)->flags,
+		p->sched_info.last_arrival);
 
 	print_worker_info(KERN_INFO, p);
 	print_stop_info(KERN_INFO, p);
-- 
2.7.4