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Subject[PATCH tip/core/rcu 3/4] locktorture: Use private random-number generators
Date
From: "Paul E. McKenney" <paulmck@kernel.org>

Both lock_torture_writer() and lock_torture_reader() use the "static"
keyword on their DEFINE_TORTURE_RANDOM(rand) declarations, which means
that a single instance of a random-number generator are shared among all
the writers and another is shared among all the readers. Unfortunately,
this random-number generator was not designed for concurrent access.
This commit therefore removes both "static" keywords so that each reader
and each writer gets its own random-number generator.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/locking/locktorture.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 687c1d8..5baf904 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -618,7 +618,7 @@ static struct lock_torture_ops percpu_rwsem_lock_ops = {
static int lock_torture_writer(void *arg)
{
struct lock_stress_stats *lwsp = arg;
- static DEFINE_TORTURE_RANDOM(rand);
+ DEFINE_TORTURE_RANDOM(rand);

VERBOSE_TOROUT_STRING("lock_torture_writer task started");
set_user_nice(current, MAX_NICE);
@@ -655,7 +655,7 @@ static int lock_torture_writer(void *arg)
static int lock_torture_reader(void *arg)
{
struct lock_stress_stats *lrsp = arg;
- static DEFINE_TORTURE_RANDOM(rand);
+ DEFINE_TORTURE_RANDOM(rand);

VERBOSE_TOROUT_STRING("lock_torture_reader task started");
set_user_nice(current, MAX_NICE);
--
2.9.5
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