All of lore.kernel.org
 help / color / mirror / Atom feed
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


  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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220204235327.2948-3-paulmck@kernel.org \
    --to=paulmck@kernel.org \
    --cc=kernel-team@fb.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rcu@vger.kernel.org \
    --cc=rostedt@goodmis.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.