Commit-ID: b8d57a76d9f92aa63b4f12990da5697b17000b0c
Gitweb: http://git.kernel.org/tip/b8d57a76d9f92aa63b4f12990da5697b17000b0c
Author: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
AuthorDate: Tue, 8 Sep 2009 15:54:35 -0700
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Fri, 18 Sep 2009 00:05:34 +0200
rcutorture: Occasionally delay readers enough to make RCU force_quiescent_state
rcutorture already delays readers, but never for long enough to
make RCU force a quiescent state. Add an occasional delay of
50ms.
Signed-off-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: laijs@xxxxxxxxxxxxxx
Cc: dipankar@xxxxxxxxxx
Cc: akpm@xxxxxxxxxxxxxxxxxxxx
Cc: mathieu.desnoyers@xxxxxxxxxx
Cc: josht@xxxxxxxxxxxxxxxxxx
Cc: dvhltc@xxxxxxxxxx
Cc: niv@xxxxxxxxxx
Cc: peterz@xxxxxxxxxxxxx
LKML-Reference: <12524504772607-git-send-email->
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/rcutorture.c | 15 +++++++++------
1 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index b33db53..328a825 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -281,14 +281,17 @@ static int rcu_torture_read_lock(void) __acquires(RCU)
static void rcu_read_delay(struct rcu_random_state *rrsp)
{
- long delay;
- const long longdelay = 200;
+ const unsigned long shortdelay_us = 200;
+ const unsigned long longdelay_ms = 50;
- /* We want there to be long-running readers, but not all the time. */
+ /* We want a short delay sometimes to make a reader delay the grace
+ * period, and we want a long delay occasionally to trigger
+ * force_quiescent_state. */
- delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay);
- if (!delay)
- udelay(longdelay);
+ if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms)))
+ mdelay(longdelay_ms);
+ if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
+ udelay(shortdelay_us);
}
static void rcu_torture_read_unlock(int idx) __releases(RCU)
--
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