[PATCH RFC tip/core/rcu 25/30] rcutorture: add random preemption
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From: Paul E. McKenney on 14 Jul 2010 16:20 From: Lai Jiangshan <laijs(a)cn.fujitsu.com> Add random preemption to help we to torture the preemptable rcu. srcu_read_delay() also calls rcu_read_delay() for shorter delays. Added comment to preempt_schedule() call indicating that no quiescent states happen if preemption is disabled. Signed-off-by: Lai Jiangshan <laijs(a)cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck(a)linux.vnet.ibm.com> --- kernel/rcutorture.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 6535ac8..430cb7f 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -304,6 +304,10 @@ 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(); /* No QS if preempt_disable() in effect */ +#endif } static void rcu_torture_read_unlock(int idx) __releases(RCU) @@ -537,6 +541,8 @@ 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) -- 1.7.0.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |