From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
rostedt@goodmis.org, "Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH rcu 3/8] rcutorture: Increase visibility of forward-progress hangs
Date: Fri, 4 Feb 2022 15:53:22 -0800 [thread overview]
Message-ID: <20220204235327.2948-3-paulmck@kernel.org> (raw)
In-Reply-To: <20220204235321.GA2511@paulmck-ThinkPad-P17-Gen-1>
This commit adds a few pr_alert() calls to rcutorture's forward-progress
testing in order to better diagnose shutdown-time hangs.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/rcutorture.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 00400aef58184..fefc3fa1a9c2a 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -2281,6 +2281,7 @@ static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp,
unsigned long stopat;
static DEFINE_TORTURE_RANDOM(trs);
+ pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id);
if (!cur_ops->sync)
return; // Cannot do need_resched() forward progress testing without ->sync.
if (cur_ops->call && cur_ops->cb_barrier) {
@@ -2325,6 +2326,7 @@ static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp,
if (selfpropcb) {
WRITE_ONCE(fcs.stop, 1);
cur_ops->sync(); /* Wait for running CB to complete. */
+ pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id);
cur_ops->cb_barrier(); /* Wait for queued callbacks. */
}
@@ -2353,6 +2355,7 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp)
unsigned long stopat;
unsigned long stoppedat;
+ pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id);
if (READ_ONCE(rcu_fwd_emergency_stop))
return; /* Get out of the way quickly, no GP wait! */
if (!cur_ops->call)
@@ -2414,6 +2417,7 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp)
n_launders_cb_snap = READ_ONCE(rfp->n_launders_cb);
cver = READ_ONCE(rcu_torture_current_version) - cver;
gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps);
+ pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id);
cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */
(void)rcu_torture_fwd_prog_cbfree(rfp);
--
2.31.1.189.g2e36527f23
next prev parent reply other threads:[~2022-02-04 23:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-04 23:53 [PATCH rcu 0/8] Torture-test updates for v5.18 Paul E. McKenney
2022-02-04 23:53 ` [PATCH rcu 1/8] rcutorture: Print message before invoking ->cb_barrier() Paul E. McKenney
2022-02-04 23:53 ` [PATCH rcu 2/8] torture: Distinguish kthread stopping and being asked to stop Paul E. McKenney
2022-02-04 23:53 ` Paul E. McKenney [this message]
2022-02-04 23:53 ` [PATCH rcu 4/8] rcutorture: Make rcu_fwd_cb_nodelay be a counter Paul E. McKenney
2022-02-04 23:53 ` [PATCH rcu 5/8] rcutorture: Add end-of-test check to rcu_torture_fwd_prog() loop Paul E. McKenney
2022-02-04 23:53 ` [PATCH rcu 6/8] rcutorture: Fix rcu_fwd_mutex deadlock Paul E. McKenney
2022-02-04 23:53 ` [PATCH rcu 7/8] torture: Wake up kthreads after storing task_struct pointer Paul E. McKenney
2022-02-04 23:53 ` [PATCH rcu 8/8] rcutorture: Enable limited callback-flooding tests of SRCU Paul E. McKenney
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