Commit-ID: 61670adcb4a9f66ff3fa8a9e846a623d9a9e1553
Gitweb: https://git.kernel.org/tip/61670adcb4a9f66ff3fa8a9e846a623d9a9e1553
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
AuthorDate: Mon, 1 Oct 2018 13:27:41 -0700
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
CommitDate: Sat, 1 Dec 2018 12:45:35 -0800
rcutorture: Prepare for asynchronous access to rcu_fwd_startat
Because rcutorture's forward-progress checking will trigger from an
OOM notifier, this notifier will introduce asynchronous concurrent
access to the rcu_fwd_startat variable. This commit therefore prepares
for this by converting updates to WRITE_ONCE().
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
---
kernel/rcu/rcutorture.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 36a3bc42782d..c4fd61dccedb 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1679,7 +1679,7 @@ static void rcu_torture_fwd_prog_nr(int *tested, int *tested_tries)
sd = cur_ops->stall_dur() + 1;
sd4 = (sd + fwd_progress_div - 1) / fwd_progress_div;
dur = sd4 + torture_random(&trs) % (sd - sd4);
- rcu_fwd_startat = jiffies;
+ WRITE_ONCE(rcu_fwd_startat, jiffies);
stopat = rcu_fwd_startat + dur;
while (time_before(jiffies, stopat) && !torture_must_stop()) {
idx = cur_ops->readlock();
@@ -1728,7 +1728,7 @@ static void rcu_torture_fwd_prog_cr(void)
/* Loop continuously posting RCU callbacks. */
WRITE_ONCE(rcu_fwd_cb_nodelay, true);
cur_ops->sync(); /* Later readers see above write. */
- rcu_fwd_startat = jiffies;
+ WRITE_ONCE(rcu_fwd_startat, jiffies);
stopat = rcu_fwd_startat + MAX_FWD_CB_JIFFIES;
n_launders = 0;
n_launders_cb = 0;
|