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

From: Paul E. McKenney
Date: Thu Aug 01 2024 - 20:44:40 EST


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 <paulmck@xxxxxxxxxx>
---
kernel/rcu/rcuscale.c | 6 ++++++
1 file changed, 6 insertions(+)

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();
--
2.40.1