rcutorture: Occasionally delay readers enough to make RCU force_quiescent_state (b8d57a76) · Commits · 戴 / test

rcutorture already delays readers, but never for long enough to make RCU force a quiescent state. Add an occasional delay of 50ms. Signed-off-by:

Josh Triplett <josh@joshtriplett.org> Signed-off-by:

Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by:

Steven Rostedt <rostedt@goodmis.org> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org LKML-Reference: <12524504772607-git-send-email-> Signed-off-by:

Ingo Molnar <mingo@elte.hu>

kernel/rcutorture.c

+9 −6

Original line number	Diff line number	Diff line
		@@ -281,14 +281,17 @@ static int rcu_torture_read_lock(void) __acquires(RCU)

		static void rcu_read_delay(struct rcu_random_state *rrsp)
		{
		long delay;
		const long longdelay = 200;
		const unsigned long shortdelay_us = 200;
		const unsigned long longdelay_ms = 50;

		/* We want there to be long-running readers, but not all the time. */
		/* We want a short delay sometimes to make a reader delay the grace
		* period, and we want a long delay occasionally to trigger
		* force_quiescent_state. */

		delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay);
		if (!delay)
		udelay(longdelay);
		if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms)))
		mdelay(longdelay_ms);
		if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
		udelay(shortdelay_us);
		}

		static void rcu_torture_read_unlock(int idx) __releases(RCU)

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