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From: paulmck@kernel.org
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
	mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com,
	akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
	josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
	rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
	fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org,
	"Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH tip/core/rcu 06/18] rcutorture: Suppress boottime bad-sequence warnings
Date: Fri, 14 Feb 2020 16:36:59 -0800
Message-ID: <20200215003711.16463-6-paulmck@kernel.org> (raw)
In-Reply-To: <20200215003634.GA16227@paulmck-ThinkPad-P72>

From: "Paul E. McKenney" <paulmck@kernel.org>

In normal production, an excessively long wait on a grace period
(synchronize_rcu(), for example) at boottime is often just as bad
as at any other time.  In fact, given the desire for fast boot, any
sort of long wait at boot is a bad idea.  However, heavy rcutorture
testing on large hyperthreaded systems can generate such long waits
during boot as a matter of course.  This commit therefore causes
the rcupdate.rcu_cpu_stall_suppress_at_boot kernel boot parameter to
suppress reporting of bootime bad-sequence warning due to excessively
long grace-period waits.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/rcutorture.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 16c84ec..5efd950 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1423,7 +1423,8 @@ rcu_torture_stats_print(void)
 	pr_alert("%s%s ", torture_type, TORTURE_FLAG);
 	pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
 		rcu_torture_current,
-		rcu_torture_current ? "ver" : "VER",
+		rcu_torture_current && !rcu_stall_is_suppressed_at_boot()
+			? "ver" : "VER",
 		rcu_torture_current_version,
 		list_empty(&rcu_torture_freelist),
 		atomic_read(&n_rcu_torture_alloc),
-- 
2.9.5


  parent reply index

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-15  0:36 [PATCH tip/core/rcu 0/18] Torture-test updates for v5.7 Paul E. McKenney
2020-02-15  0:36 ` [PATCH tip/core/rcu 01/18] rcutorture: Suppress forward-progress complaints during early boot paulmck
2020-02-15  0:36 ` [PATCH tip/core/rcu 02/18] torture: Make results-directory date format completion-friendly paulmck
2020-02-15  0:36 ` [PATCH tip/core/rcu 03/18] rcutorture: Refrain from callback flooding during boot paulmck
2020-02-15  0:36 ` [PATCH tip/core/rcu 04/18] torture: Forgive -EBUSY from boottime CPU-hotplug operations paulmck
2020-02-15  0:36 ` [PATCH tip/core/rcu 05/18] rcutorture: Allow boottime stall warnings to be suppressed paulmck
2020-02-15  0:36 ` paulmck [this message]
2020-02-15  0:41 ` [PATCH tip/core/rcu 07/18] torture: Allow disabling of boottime CPU-hotplug torture operations paulmck
2020-02-15  0:41 ` [PATCH tip/core/rcu 08/18] rcutorture: Add 100-CPU configuration paulmck
2020-02-15  0:41 ` [PATCH tip/core/rcu 09/18] rcutorture: Summarize summary of build and run results paulmck
2020-02-15  0:41 ` [PATCH tip/core/rcu 10/18] rcutorture: Make kvm-find-errors.sh abort on bad directory paulmck
2020-02-15  0:41 ` [PATCH tip/core/rcu 11/18] rcutorture: Fix rcu_torture_one_read()/rcu_torture_writer() data race paulmck
2020-02-15  0:41 ` [PATCH tip/core/rcu 12/18] rcutorture: Fix stray access to rcu_fwd_cb_nodelay paulmck
2020-02-15  0:41 ` [PATCH tip/core/rcu 13/18] rcutorture: Add READ_ONCE() to rcu_torture_count and rcu_torture_batch paulmck
2020-02-15  0:41 ` [PATCH tip/core/rcu 14/18] rcutorture: Annotation lockless accesses to rcu_torture_current paulmck
2020-02-15  0:41 ` [PATCH tip/core/rcu 15/18] rcuperf: Measure memory footprint during kfree_rcu() test paulmck
2020-02-15  0:41 ` [PATCH tip/core/rcu 16/18] rcutorture: Make rcu_torture_barrier_cbs() post from corresponding CPU paulmck
2020-02-15  0:41 ` [PATCH tip/core/rcu 17/18] rcutorture: Manually clean up after rcu_barrier() failure paulmck
2020-02-15  0:41 ` [PATCH tip/core/rcu 18/18] rcutorture: Set KCSAN Kconfig options to detect more data races paulmck

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