Commit 6b3de7a1 authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Paul E. McKenney
Browse files

rcutorture: Break up too-long rcu_torture_fwd_prog() function 



This commit splits rcu_torture_fwd_prog_nr() and rcu_torture_fwd_prog_cr()
functions out of rcu_torture_fwd_prog() in order to reduce indentation
pain and because rcu_torture_fwd_prog() was getting a bit too long.
In addition, this will enable easier conditional execution of the
rcu_torture_fwd_prog_cr() function, which can give false-positive
failures in some NO_HZ_FULL configurations due to overloading the
housekeeping CPUs.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent fc6f9c57

kernel/rcu/rcutorture.c

+135 −119
Original line number Diff line number Diff line
@@ -1650,41 +1650,24 @@ static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp) 
	spin_unlock(&rcu_fwd_lock);

}



/* Carry out grace-period forward-progress testing. */

static int rcu_torture_fwd_prog(void *args)

/* Carry out need_resched()/cond_resched() forward-progress testing. */

static void rcu_torture_fwd_prog_nr(int *tested, int *tested_tries)

{

	unsigned long cver;

	unsigned long dur;

	struct fwd_cb_state fcs;

	unsigned long gps;

	int i;

	int idx;

	int j;

	long n_launders;

	long n_launders_cb_snap;

	long n_launders_sa;

	long n_max_cbs;

	long n_max_gps;

	struct rcu_fwd_cb *rfcp;

	struct rcu_fwd_cb *rfcpn;

	int sd;

	int sd4;

	bool selfpropcb = false;

	unsigned long stopat;

	unsigned long stoppedat;

	int tested = 0;

	int tested_tries = 0;

	static DEFINE_TORTURE_RANDOM(trs);



	VERBOSE_TOROUT_STRING("rcu_torture_fwd_progress task started");

	if (!IS_ENABLED(CONFIG_SMP) || !IS_ENABLED(CONFIG_RCU_BOOST))

		set_user_nice(current, MAX_NICE);

	if  (cur_ops->call && cur_ops->sync && cur_ops->cb_barrier) {

		init_rcu_head_on_stack(&fcs.rh);

		selfpropcb = true;

	}

	do {

		schedule_timeout_interruptible(fwd_progress_holdoff * HZ);



	/* Tight loop containing cond_resched(). */

	if  (selfpropcb) {
@@ -1705,9 +1688,9 @@ static int rcu_torture_fwd_prog(void *args) 
		if (!fwd_progress_need_resched || need_resched())

			cond_resched();

	}

		tested_tries++;

	(*tested_tries)++;

	if (!time_before(jiffies, stopat) && !torture_must_stop()) {

			tested++;

		(*tested)++;

		cver = READ_ONCE(rcu_torture_current_version) - cver;

		gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps);

		WARN_ON(!cver && gps < 2);
@@ -1719,6 +1702,29 @@ static int rcu_torture_fwd_prog(void *args) 
		cur_ops->cb_barrier(); /* Wait for queued callbacks. */

	}



	if (selfpropcb) {

		WARN_ON(READ_ONCE(fcs.stop) != 2);

		destroy_rcu_head_on_stack(&fcs.rh);

	}

}



/* Carry out call_rcu() forward-progress testing. */

static void rcu_torture_fwd_prog_cr(void)

{

	unsigned long cver;

	unsigned long gps;

	int i;

	int j;

	long n_launders;

	long n_launders_cb_snap;

	long n_launders_sa;

	long n_max_cbs;

	long n_max_gps;

	struct rcu_fwd_cb *rfcp;

	struct rcu_fwd_cb *rfcpn;

	unsigned long stopat;

	unsigned long stoppedat;



	/* Loop continuously posting RCU callbacks. */

	WRITE_ONCE(rcu_fwd_cb_nodelay, true);

	cur_ops->sync(); /* Later readers see above write. */
@@ -1776,8 +1782,7 @@ static int rcu_torture_fwd_prog(void *args) 
		WARN_ON(n_max_gps < MIN_FWD_CBS_LAUNDERED);

		pr_alert("%s Duration %lu barrier: %lu pending %ld n_launders: %ld n_launders_sa: %ld n_max_gps: %ld n_max_cbs: %ld cver %ld gps %ld\n",

			 __func__,

				 stoppedat - rcu_fwd_startat,

				 jiffies - stoppedat,

			 stoppedat - rcu_fwd_startat, jiffies - stoppedat,

			 n_launders + n_max_cbs - n_launders_cb_snap,

			 n_launders, n_launders_sa,

			 n_max_gps, n_max_cbs, cver, gps);
@@ -1789,14 +1794,25 @@ static int rcu_torture_fwd_prog(void *args) 
			pr_cont(" %ds: %ld", j + 1, n_launders_hist[j]);

		pr_cont("\n");

	}

}



/* Carry out grace-period forward-progress testing. */

static int rcu_torture_fwd_prog(void *args)

{

	int tested = 0;

	int tested_tries = 0;



	VERBOSE_TOROUT_STRING("rcu_torture_fwd_progress task started");

	if (!IS_ENABLED(CONFIG_SMP) || !IS_ENABLED(CONFIG_RCU_BOOST))

		set_user_nice(current, MAX_NICE);

	do {

		schedule_timeout_interruptible(fwd_progress_holdoff * HZ);

		rcu_torture_fwd_prog_nr(&tested, &tested_tries);

		rcu_torture_fwd_prog_cr();



		/* Avoid slow periods, better to test when busy. */

		stutter_wait("rcu_torture_fwd_prog");

	} while (!torture_must_stop());

	if (selfpropcb) {

		WARN_ON(READ_ONCE(fcs.stop) != 2);

		destroy_rcu_head_on_stack(&fcs.rh);

	}

	/* Short runs might not contain a valid forward-progress attempt. */

	WARN_ON(!tested && tested_tries >= 5);

	pr_alert("%s: tested %d tested_tries %d\n", __func__, tested, tested_tries);

CRA Git | Maintained and supported by SUSTech CRA and CCSE