From: Lai Jiangshan <laijs@cn.fujitsu.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH] rcutorture: add random preemption
Date: Mon, 21 Jun 2010 16:57:42 +0800 [thread overview]
Message-ID: <4C1F2986.7080006@cn.fujitsu.com> (raw)
Add random preemption to help we to torture the preemptable rcu.
srcu_read_delay() also calls rcu_read_delay() for shorter delays.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 2e2726d..7c81d07 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -303,6 +303,10 @@ static void rcu_read_delay(struct rcu_random_state *rrsp)
mdelay(longdelay_ms);
if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
udelay(shortdelay_us);
+#ifdef CONFIG_PREEMPT
+ if (!preempt_count() && !(rcu_random(rrsp) % (nrealreaders * 20000)))
+ preempt_schedule();
+#endif
}
static void rcu_torture_read_unlock(int idx) __releases(RCU)
@@ -536,6 +540,8 @@ static void srcu_read_delay(struct rcu_random_state *rrsp)
delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick);
if (!delay)
schedule_timeout_interruptible(longdelay);
+ else
+ rcu_read_delay(rrsp);
}
static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl)
next reply other threads:[~2010-06-21 8:57 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-21 8:57 Lai Jiangshan [this message]
2010-06-21 16:43 ` [PATCH] rcutorture: add random preemption Paul E. McKenney
2010-06-21 16:50 ` Peter Zijlstra
2010-06-21 17:05 ` Paul E. McKenney
2010-06-21 17:06 ` Peter Zijlstra
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