From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: kernel-team@meta.com,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Boqun Feng <boqun@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
lkmm@lists.linux.dev, Zqiang <qiang.zhang@linux.dev>,
Wang Lian <lianux.mm@gmail.com>,
Kunwu Chan <kunwu.chan@gmail.com>,
Bradley Morgan <brads@mainlining.org>,
"Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH 05/28] hazptrtorture: Add microsecond-scale sleep in readers
Date: Fri, 18 Sep 2026 17:00:33 -0700 [thread overview]
Message-ID: <20260919000056.3132131-5-paulmck@kernel.org> (raw)
In-Reply-To: <e9669b34-12c2-4cf2-a887-315f581f0789@paulmck-laptop>
This commit adds a default-disabled reader_sleep_us module parameter
that causes the hazard-pointer reader to unconditionally sleep for the
specified number of microseconds.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: <rcu@vger.kernel.org>
Cc: <lkmm@lists.linux.dev>
---
kernel/rcu/hazptrtorture.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/rcu/hazptrtorture.c b/kernel/rcu/hazptrtorture.c
index 22a0610d0dbd..9ecb86520551 100644
--- a/kernel/rcu/hazptrtorture.c
+++ b/kernel/rcu/hazptrtorture.c
@@ -35,6 +35,7 @@ torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
torture_param(int, onoff_interval, 0, "Time between CPU hotplugs (jiffies), 0=disable");
torture_param(int, preempt_duration, 0, "Preemption duration (ms), zero to disable");
torture_param(int, preempt_interval, MSEC_PER_SEC, "Interval between preemptions (ms)");
+torture_param(int, reader_sleep_us, 0, "Reader sleep duration (us)");
torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
torture_param(int, stat_interval, 60, "Number of seconds between stats printk()s");
@@ -219,6 +220,8 @@ static void hazptr_read_delay(struct torture_random_state *rrsp)
udelay(shortdelay_us);
if (!preempt_count() && !(torture_random(rrsp) % (nrealreaders * 500)))
torture_preempt_schedule(); /* QS only if preemptible. */
+ if (reader_sleep_us > 0)
+ torture_hrtimeout_us(reader_sleep_us, 0, NULL);
}
static void hazptr_torture_read_unlock(struct hazptr_ctx *hcp, struct hazptr_torture *htp)
@@ -507,11 +510,13 @@ hazptr_torture_print_module_parms(struct hazptr_torture_ops *cur_ops, const char
"--- %s: nreaders=%d "
"onoff_interval=%d onoff_holdoff=%d "
"preempt_duration=%d preempt_interval=%d "
+ "reader_sleep_us=%d "
"shuffle_interval=%d shutdown_secs=%d stat_interval=%d stutter=%d "
"verbose=%d\n",
torture_type, tag, nrealreaders,
onoff_interval, onoff_holdoff,
preempt_duration, preempt_interval,
+ reader_sleep_us,
shuffle_interval, shutdown_secs, stat_interval, stutter,
verbose);
}
--
2.40.1
next prev parent reply other threads:[~2026-09-19 0:01 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-18 23:59 [PATCH RFC v3 0/28] Simple hazard-pointer implementation and torture tests Paul E. McKenney
2026-09-19 0:00 ` [PATCH 01/28] hazptr: Implement Hazard Pointers Paul E. McKenney
2026-09-19 11:12 ` Bradley Morgan
2026-09-19 0:00 ` [PATCH 02/28] hazptr: Add refscale test Paul E. McKenney
2026-09-19 0:00 ` [PATCH 03/28] torture: Add a hazptrtorture.c torture test Paul E. McKenney
2026-09-19 0:00 ` [PATCH 04/28] hazptrtorture: Add testing of on-stack hazptr_ctx structures Paul E. McKenney
2026-09-19 0:00 ` Paul E. McKenney [this message]
2026-09-19 0:00 ` [PATCH 06/28] hazptrtorture: Enable system-independent CPU overcommit Paul E. McKenney
2026-09-19 0:00 ` [PATCH 07/28] torture: Add a stutter_will_wait() function Paul E. McKenney
2026-09-19 0:00 ` [PATCH 08/28] hazptrtorture: Use mnemonic local variables for context information Paul E. McKenney
2026-09-19 0:00 ` [PATCH 09/28] hazptrtorture: Split hazptr_torture_reader_tail() from hazptr_torture_reader() Paul E. McKenney
2026-09-19 0:00 ` [PATCH 10/28] hazptrtorture: Add kthread to release deferred hazard pointers Paul E. McKenney
2026-09-19 0:00 ` [PATCH 11/28] hazptrtorture: Defer release of " Paul E. McKenney
2026-09-19 0:00 ` [PATCH 12/28] hazptrtorture: Add irq_acquire to acquire hazptr from irq Paul E. McKenney
2026-09-19 0:00 ` [PATCH 13/28] hazptrtorture: Use task_state_to_char() for task-state reporting Paul E. McKenney
2026-09-19 0:00 ` [PATCH 14/28] hazptrtorture: Pass hazptr_pending to hazptr_torture_reader_tail() Paul E. McKenney
2026-09-19 0:00 ` [PATCH 15/28] hazptrtorture: Add the ability to disable the writer kthread Paul E. McKenney
2026-09-19 0:00 ` [PATCH 16/28] hazptrtorture: Add irq_release to release hazptr from irq Paul E. McKenney
2026-09-19 0:00 ` [PATCH 17/28] hazptrtorture: Accumulate operation statistics Paul E. McKenney
2026-09-19 0:00 ` [PATCH 18/28] doc: Add hazptrtorture module parameters Paul E. McKenney
2026-09-19 0:00 ` [PATCH 19/28] hazptr: Permit detaching hazard pointers from contexts Paul E. McKenney
2026-09-19 11:42 ` Boqun Feng
2026-09-19 11:43 ` Boqun Feng
2026-09-19 0:00 ` [PATCH 20/28] hazptrtorture: Detach deferred and IPIed hazard pointers Paul E. McKenney
2026-09-19 0:00 ` [PATCH 21/28] hazptr: Introduce CONFIG_HAZPTR_DEBUG misuse detection Paul E. McKenney
2026-09-19 0:00 ` [PATCH 22/28] hazptrtorture: Fix hazptr ownership issue Paul E. McKenney
2026-09-19 0:00 ` [PATCH 23/28] hazptrtorture: Enable CONFIG_HAZPTR_DEBUG Paul E. McKenney
2026-09-19 0:00 ` [PATCH 24/28] hazptr: Upgrade kernel-doc headers Paul E. McKenney
2026-09-19 0:00 ` [PATCH 25/28] hazptrtorture: Fix inverted sleep condition in do_pending kthread Paul E. McKenney
2026-09-19 0:00 ` [PATCH 26/28] hazptr: Implement two-phase wildcard scan Paul E. McKenney
2026-09-19 13:28 ` Boqun Feng
2026-09-19 0:00 ` [PATCH 27/28] hazptr: handle NULL address in hazptr_detach Paul E. McKenney
2026-09-19 0:00 ` [PATCH 28/28] torture.sh: Add hazptr torturing Paul E. McKenney
2026-09-19 11:18 ` Bradley Morgan
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