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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,
	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 06/17] rcutorture: Make rcu_torture_fakewriter() use blocking wait primitives
Date: Wed,  6 Jan 2021 09:16:59 -0800
Message-ID: <20210106171710.22239-6-paulmck@kernel.org> (raw)
In-Reply-To: <20210106171532.GA20769@paulmck-ThinkPad-P72>

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

Full testing of the new SRCU polling API requires that the fake
writers also use it in order to test concurrent calls to all of the API
members, especially start_poll_synchronize_srcu().  This commit makes
rcu_torture_fakewriter() use all available blocking grace-period-wait
primitives available from the RCU flavor under test.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/rcutorture.c | 40 ++++++++++++++++++++++++++++++++--------
 1 file changed, 32 insertions(+), 8 deletions(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index ea44a2b..1b70aa4 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1289,6 +1289,8 @@ rcu_torture_writer(void *arg)
 static int
 rcu_torture_fakewriter(void *arg)
 {
+	unsigned long gp_snap;
+	int i;
 	DEFINE_TORTURE_RANDOM(rand);
 
 	VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
@@ -1300,15 +1302,37 @@ rcu_torture_fakewriter(void *arg)
 		if (cur_ops->cb_barrier != NULL &&
 		    torture_random(&rand) % (nfakewriters * 8) == 0) {
 			cur_ops->cb_barrier();
-		} else if (gp_normal == gp_exp) {
-			if (cur_ops->sync && torture_random(&rand) & 0x80)
-				cur_ops->sync();
-			else if (cur_ops->exp_sync)
+		} else {
+			switch (synctype[torture_random(&rand) % nsynctypes]) {
+			case RTWS_DEF_FREE:
+				break;
+			case RTWS_EXP_SYNC:
 				cur_ops->exp_sync();
-		} else if (gp_normal && cur_ops->sync) {
-			cur_ops->sync();
-		} else if (cur_ops->exp_sync) {
-			cur_ops->exp_sync();
+				break;
+			case RTWS_COND_GET:
+				gp_snap = cur_ops->get_gp_state();
+				i = torture_random(&rand) % 16;
+				if (i != 0)
+					schedule_timeout_interruptible(i);
+				udelay(torture_random(&rand) % 1000);
+				cur_ops->cond_sync(gp_snap);
+				break;
+			case RTWS_POLL_GET:
+				gp_snap = cur_ops->start_gp_poll();
+				while (!cur_ops->poll_gp_state(gp_snap)) {
+					i = torture_random(&rand) % 16;
+					if (i != 0)
+						schedule_timeout_interruptible(i);
+					udelay(torture_random(&rand) % 1000);
+				}
+				break;
+			case RTWS_SYNC:
+				cur_ops->sync();
+				break;
+			default:
+				WARN_ON_ONCE(1);
+				break;
+			}
 		}
 		stutter_wait("rcu_torture_fakewriter");
 	} while (!torture_must_stop());
-- 
2.9.5


  parent reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-06 17:15 [PATCH tip/core/rcu 0/17] Torture-test updates for v5.12 Paul E. McKenney
2021-01-06 17:16 ` [PATCH tip/core/rcu 01/17] rcutorture: Add testing for RCU's global memory ordering paulmck
2021-01-06 17:16 ` [PATCH tip/core/rcu 02/17] scftorture: Add debug output for wrong-CPU warning paulmck
2021-01-06 17:16 ` [PATCH tip/core/rcu 03/17] refscale: Allow summarization of verbose output paulmck
2021-01-06 17:16 ` [PATCH tip/core/rcu 04/17] rcutorture: Require entire stutter period be post-boot paulmck
2021-01-06 17:16 ` [PATCH tip/core/rcu 05/17] rcutorture: Make synctype[] and nsynctype be static global paulmck
2021-01-06 17:16 ` paulmck [this message]
2021-01-06 17:17 ` [PATCH tip/core/rcu 07/17] torture: Add fuzzed hrtimer-based sleep functions paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 08/17] rcutorture: Use torture_hrtimeout_jiffies() to avoid busy-waits paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 09/17] torture: Make stutter use torture_hrtimeout_*() functions paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 10/17] rcutorture: Use hrtimers for reader and writer delays paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 11/17] torture: Make refscale throttle high-rate printk()s paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 12/17] torture: Throttle VERBOSE_TOROUT_*() output paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 13/17] rcutorture: Make object_debug also double call_rcu() heap object paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 14/17] torture: Clean up after torture-test CPU hotplugging paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 15/17] torture: Maintain torture-specific set of CPUs-online books paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 16/17] torture: Break affinity of kthreads last running on outgoing CPU paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 17/17] rcutorture: Add rcutree.use_softirq=0 to RUDE01 and TASKS01 paulmck

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