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From: "Paul E. McKenney" <paulmck@linux.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: 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@linux.ibm.com>
Subject: [PATCH tip/core/rcu 17/17] rcutorture: Don't do busted forward-progress testing
Date: Sun, 11 Nov 2018 12:20:27 -0800	[thread overview]
Message-ID: <20181111202027.13585-17-paulmck@linux.ibm.com> (raw)
In-Reply-To: <20181111201956.GA11935@linux.ibm.com>

The "busted" rcutorture type is an intentionally broken implementation
of RCU.  Doing forward-progress testing on this implementation is not
particularly meaningful on the one hand and can result in fatal abuse
of the memory allocator on the other.  This commit therefore disables
forward-progress testing of the "busted" rcutorture type.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 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 a4c4a24bdcaa..f6e85faa4ff4 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1900,7 +1900,8 @@ static int __init rcu_torture_fwd_prog_init(void)
 {
 	if (!fwd_progress)
 		return 0; /* Not requested, so don't do it. */
-	if (!cur_ops->stall_dur || cur_ops->stall_dur() <= 0) {
+	if (!cur_ops->stall_dur || cur_ops->stall_dur() <= 0 ||
+	    cur_ops == &rcu_busted_ops) {
 		VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test");
 		return 0;
 	}
-- 
2.17.1


      parent reply	other threads:[~2018-11-11 20:21 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-11 20:19 [PATCH tip/core/rcu 0/17] Torture-test updates for v4.21/v5.0 Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 01/17] rcutorture: Add call_rcu() flooding forward-progress tests Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 02/17] torture: Bring any extra CPUs online during kernel startup Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 03/17] rcutorture: Remove cbflood facility Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 04/17] rcutorture: Break up too-long rcu_torture_fwd_prog() function Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 05/17] rcutorture: Affinity forward-progress test to avoid housekeeping CPUs Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 06/17] torture: Remove unnecessary "ret" variables Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 07/17] rcutorture: Prepare for asynchronous access to rcu_fwd_startat Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 08/17] rcutorture: Dump grace-period diagnostics upon forward-progress OOM Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 09/17] rcu: Account for nocb-CPU callback counts in RCU CPU stall warnings Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 10/17] rcu: Print per-CPU callback counts for forward-progress failures Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 11/17] rcutorture: Print GP age upon forward-progress failure Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 12/17] rcutorture: Print histogram of CB invocation at OOM time Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 13/17] rcutorture: Print time since GP end upon forward-progress failure Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 14/17] rcutorture: Print forward-progress test age upon failure Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 15/17] rcutorture: Recover from OOM during forward-progress tests Paul E. McKenney
2018-11-11 20:20 ` [PATCH tip/core/rcu 16/17] rcutorture: Use 100ms buckets for forward-progress callback histograms Paul E. McKenney
2018-11-11 20:20 ` Paul E. McKenney [this message]

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