[07/11] rcuscale: Make all writer tasks report upon hang

Commit Message

Paul E. McKenney Aug. 2, 2024, 12:43 a.m. UTC

This commit causes all writer tasks to provide a brief report after a
hang has been reported, spaced at one-second intervals.

Signed-off-by: Paul E. McKenney <[e-mail]>
---
 kernel/rcu/rcuscale.c | 6 ++++++
 1 file changed, 6 insertions(+)

Patch

diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
index 315ced63ec105..a820f11b19444 100644
--- a/kernel/rcu/rcuscale.c
+++ b/kernel/rcu/rcuscale.c
@@ -483,6 +483,7 @@  rcu_scale_writer(void *arg)
 	unsigned long jdone;
 	long me = (long)arg;
 	struct rcu_head *rhp = NULL;
+	bool selfreport = false;
 	bool started = false, done = false, alldone = false;
 	u64 t;
 	DEFINE_TORTURE_RANDOM(tr);
@@ -593,6 +594,11 @@  rcu_scale_writer(void *arg)
 					cur_ops->stats();
 			}
 		}
+		if (!selfreport && time_after(jiffies, jdone + HZ * (70 + me))) {
+			pr_info("%s: Writer %ld self-report: started %d done %d/%d->%d i %d jdone %lu.\n",
+				__func__, me, started, done, writer_done[me], atomic_read(&n_rcu_scale_writer_finished), i, jiffies - jdone);
+			selfreport = true;
+		}
 		if (started && !alldone && i < MAX_MEAS - 1)
 			i++;
 		rcu_scale_wait_shutdown();