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| author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2010-06-21 16:57:42 +0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-08-19 17:18:01 -0700 |
| commit | e546f485e1d7520ca0200502cdcc11b503f4805c (patch) | |
| tree | 14a62f4f56eb6bb96f2621b5334dac5a3c5c4160 | |
| parent | 84483ea42cd4f2781d6e97a83ab3ebd0ff19fb10 (diff) | |
| download | lwn-e546f485e1d7520ca0200502cdcc11b503f4805c.tar.gz lwn-e546f485e1d7520ca0200502cdcc11b503f4805c.zip | |
rcutorture: add random preemption
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@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| -rw-r--r-- | kernel/rcutorture.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 2e2726d790b9..729710273dcb 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(); /* No QS if preempt_disable() in effect */ +#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) |