rcutorture: Prepare for asynchronous access to rcu_fwd_startat (61670adc) · Commits · 戴 / test

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@linux.ibm.com>

kernel/rcu/rcutorture.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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;

Admin message