lkml.org 
[lkml]   [2012]   [Sep]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH tip/core/rcu 17/23] rcu: Add random PROVE_RCU_DELAY to grace-period initialization
Date
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

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>
---
kernel/rcutree.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 25a671c..5cb003d 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>
@@ -1085,6 +1086,10 @@ 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();
}

--
1.7.8


\
 
 \ /
  Last update: 2012-09-20 22:41    [W:0.201 / U:0.552 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site