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From:   Yajun Deng <yajun.deng@linux.dev>
To:     mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
        vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
        rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
        bristot@redhat.com, vschneid@redhat.com
Cc:     linux-kernel@vger.kernel.org, Yajun Deng <yajun.deng@linux.dev>
Subject: [PATCH] sched/rt: Add pid and comm when RT throttling activated
Date:   Tue,  6 Dec 2022 16:36:41 +0800
Message-Id: <20221206083641.103832-1-yajun.deng@linux.dev>
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It is difficult to know which process consumes time when RT throttling
activated.

So add pid and comm for this case.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
---
 kernel/sched/rt.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index ed2a47e4ddae..1f267ab1b59a 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1012,6 +1012,7 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
 
 	if (rt_rq->rt_time > runtime) {
 		struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
+		struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr;
 
 		/*
 		 * Don't actually throttle groups that have no runtime assigned
@@ -1019,7 +1020,8 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
 		 */
 		if (likely(rt_b->rt_runtime)) {
 			rt_rq->rt_throttled = 1;
-			printk_deferred_once("sched: RT throttling activated\n");
+			printk_deferred_once("pid: %d, comm: %s, sched: RT throttling activated\n",
+					     curr->pid, curr->comm);
 		} else {
 			/*
 			 * In case we did anyway, make it go away,
-- 
2.25.1