Commit-ID: 661a85dc0d2ec0404e3b80909e413a9d5e42a239 Gitweb: http://git.kernel.org/tip/661a85dc0d2ec0404e3b80909e413a9d5e42a239 Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> AuthorDate: Sat, 7 Jul 2012 05:57:03 -0700 Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> CommitDate: Sun, 23 Sep 2012 07:41:55 -0700 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@xxxxxxxxxxxxxxxxxx> Reviewed-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx> --- kernel/rcutree.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 145f27f..f0f3a18 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(); } -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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