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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-07-07 05:57:03 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-09-23 07:41:55 -0700 |
| commit | 661a85dc0d2ec0404e3b80909e413a9d5e42a239 (patch) | |
| tree | 8ea9545a62835d8cd47978fd31ede669f988b43a | |
| parent | 5d4b86594984d8746b01487c768d8548463c173f (diff) | |
| download | linux-661a85dc0d2ec0404e3b80909e413a9d5e42a239.tar.gz linux-661a85dc0d2ec0404e3b80909e413a9d5e42a239.tar.bz2 linux-661a85dc0d2ec0404e3b80909e413a9d5e42a239.zip | |
rcu: Add random PROVE_RCU_DELAY to grace-period initialization
Preemption greatly raised the probability of certain types of race
conditions, so this commit adds an anti-heisenbug to greatly increase
the collision cross section, also known as the probability of occurrence.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| -rw-r--r-- | kernel/rcutree.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 145f27fe3a1f..f0f3a18c0a20 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -52,6 +52,7 @@ #include <linux/prefetch.h> #include <linux/delay.h> #include <linux/stop_machine.h> +#include <linux/random.h> #include "rcutree.h" #include <trace/events/rcu.h> @@ -1087,6 +1088,10 @@ static int rcu_gp_init(struct rcu_state *rsp) rnp->level, rnp->grplo, rnp->grphi, rnp->qsmask); raw_spin_unlock_irq(&rnp->lock); +#ifdef CONFIG_PROVE_RCU_DELAY + if ((random32() % (rcu_num_nodes * 8)) == 0) + schedule_timeout_uninterruptible(2); +#endif /* #ifdef CONFIG_PROVE_RCU_DELAY */ cond_resched(); } |