Currently, the inter-stutter interval is the same as the stutter duration,
that is, whatever number of jiffies is passed into torture_stutter_init().
This has worked well for quite some time, but the addition of
forward-progress testing to rcutorture can delay processes for several
seconds, which can triple the time that they are stuttered.
This commit therefore adds a second argument to torture_stutter_init()
that specifies the inter-stutter interval. While locktorture preserves
the current behavior, rcutorture uses the RCU CPU stall warning interval
to provide a wider inter-stutter interval.
Signed-off-by: Paul E. McKenney <paul...@linux.ibm.com>
---
include/linux/torture.h | 2 +-
kernel/locking/locktorture.c | 2 +-
kernel/rcu/rcutorture.c | 5 ++++-
kernel/torture.c | 6 ++++--
4 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/include/linux/torture.h b/include/linux/torture.h
index 23d80db426d7..a620118385bb 100644
--- a/include/linux/torture.h
+++ b/include/linux/torture.h
@@ -66,7 +66,7 @@ int torture_shutdown_init(int ssecs, void (*cleanup)(void));
/* Task stuttering, which forces load/no-load transitions. */
bool stutter_wait(const char *title);
-int torture_stutter_init(int s);
+int torture_stutter_init(int s, int sgap);
/* Initialization and cleanup. */
bool torture_init_begin(char *ttype, int v);
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 80a463d31a8d..c513031cd7e3 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -975,7 +975,7 @@ static int __init lock_torture_init(void)
goto unwind;
}
if (stutter > 0) {
- firsterr = torture_stutter_init(stutter);
+ firsterr = torture_stutter_init(stutter, stutter);
if (firsterr)
goto unwind;
}
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 954ac2b98619..a16d6abe1715 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -2373,7 +2373,10 @@ rcu_torture_init(void)
if (stutter < 0)
stutter = 0;
if (stutter) {
- firsterr = torture_stutter_init(stutter * HZ);
+ int t;
+
+ t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ;
+ firsterr = torture_stutter_init(stutter * HZ, t);
if (firsterr)
goto unwind;
}
diff --git a/kernel/torture.c b/kernel/torture.c
index de0e0ecf88e1..a8d9bdfba7c3 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -570,6 +570,7 @@ static void torture_shutdown_cleanup(void)
static struct task_struct *stutter_task;
static int stutter_pause_test;
static int stutter;
+static int stutter_gap;
/*
* Block until the stutter interval ends. This must be called periodically
@@ -621,7 +622,7 @@ static int torture_stutter(void *arg)
}
WRITE_ONCE(stutter_pause_test, 0);
if (!torture_must_stop())
- schedule_timeout_interruptible(stutter);
+ schedule_timeout_interruptible(stutter_gap);
torture_shutdown_absorb("torture_stutter");
} while (!torture_must_stop());
torture_kthread_stopping("torture_stutter");
@@ -631,9 +632,10 @@ static int torture_stutter(void *arg)
/*
* Initialize and kick off the torture_stutter kthread.
*/
-int torture_stutter_init(const int s)
+int torture_stutter_init(const int s, const int sgap)
{
stutter = s;
+ stutter_gap = sgap;
return torture_create_kthread(torture_stutter, NULL, stutter_task);
}
EXPORT_SYMBOL_GPL(torture_stutter_init);
--
2.17.1
