Commit 73e34124 authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Frederic Weisbecker
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locktorture: Add readers_bind and writers_bind module parameters 



This commit adds readers_bind and writers_bind module parameters to
locktorture in order to skew tests across socket boundaries.  This skewing
is intended to provide additional variable-latency stress on the primitive
under test.

Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
parent 0cfecd7d

kernel/locking/locktorture.c

+62 −2
Original line number Diff line number Diff line
@@ -56,6 +56,55 @@ module_param(torture_type, charp, 0444); 
MODULE_PARM_DESC(torture_type,

		 "Type of lock to torture (spin_lock, spin_lock_irq, mutex_lock, ...)");



static cpumask_var_t readers_bind; // Bind the readers to the specified set of CPUs.

static cpumask_var_t writers_bind; // Bind the writers to the specified set of CPUs.



// Parse a cpumask kernel parameter.  If there are more users later on,

// this might need to got to a more central location.

static int param_set_cpumask(const char *val, const struct kernel_param *kp)

{

	cpumask_var_t *cm_bind = kp->arg;

	int ret;

	char *s;



	if (!alloc_cpumask_var(cm_bind, GFP_KERNEL)) {

		s = "Out of memory";

		ret = -ENOMEM;

		goto out_err;

	}

	ret = cpulist_parse(val, *cm_bind);

	if (!ret)

		return ret;

	s = "Bad CPU range";

out_err:

	pr_warn("%s: %s, all CPUs set\n", kp->name, s);

	cpumask_setall(*cm_bind);

	return ret;

}



// Output a cpumask kernel parameter.

static int param_get_cpumask(char *buffer, const struct kernel_param *kp)

{

	cpumask_var_t *cm_bind = kp->arg;



	return sprintf(buffer, "%*pbl", cpumask_pr_args(*cm_bind));

}



static bool cpumask_nonempty(cpumask_var_t mask)

{

	return cpumask_available(mask) && !cpumask_empty(mask);

}



static const struct kernel_param_ops lt_bind_ops = {

	.set = param_set_cpumask,

	.get = param_get_cpumask,

};



module_param_cb(readers_bind, &lt_bind_ops, &readers_bind, 0644);

module_param_cb(writers_bind, &lt_bind_ops, &writers_bind, 0644);



long torture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask);



static struct task_struct *stats_task;

static struct task_struct **writer_tasks;

static struct task_struct **reader_tasks;
@@ -986,16 +1035,23 @@ static int lock_torture_stats(void *arg) 
	return 0;

}





static inline void

lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,

				const char *tag)

{

	static cpumask_t cpumask_all;

	cpumask_t *rcmp = cpumask_nonempty(readers_bind) ? readers_bind : &cpumask_all;

	cpumask_t *wcmp = cpumask_nonempty(writers_bind) ? writers_bind : &cpumask_all;



	cpumask_setall(&cpumask_all);

	pr_alert("%s" TORTURE_FLAG

		 "--- %s%s: nwriters_stress=%d nreaders_stress=%d nested_locks=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",

		 "--- %s%s: nwriters_stress=%d nreaders_stress=%d nested_locks=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d readers_bind=%*pbl writers_bind=%*pbl\n",

		 torture_type, tag, cxt.debug_lock ? " [debug]": "",

		 cxt.nrealwriters_stress, cxt.nrealreaders_stress,

		 nested_locks, stat_interval, verbose, shuffle_interval,

		 stutter, shutdown_secs, onoff_interval, onoff_holdoff);

		 stutter, shutdown_secs, onoff_interval, onoff_holdoff,

		 cpumask_pr_args(rcmp), cpumask_pr_args(wcmp));

}



static void lock_torture_cleanup(void)
@@ -1250,6 +1306,8 @@ static int __init lock_torture_init(void) 
						     writer_fifo ? sched_set_fifo : NULL);

		if (torture_init_error(firsterr))

			goto unwind;

		if (cpumask_nonempty(writers_bind))

			torture_sched_setaffinity(writer_tasks[i]->pid, writers_bind);



	create_reader:

		if (cxt.cur_ops->readlock == NULL || (j >= cxt.nrealreaders_stress))
@@ -1259,6 +1317,8 @@ static int __init lock_torture_init(void) 
						  reader_tasks[j]);

		if (torture_init_error(firsterr))

			goto unwind;

		if (cpumask_nonempty(readers_bind))

			torture_sched_setaffinity(reader_tasks[j]->pid, readers_bind);

	}

	if (stat_interval > 0) {

		firsterr = torture_create_kthread(lock_torture_stats, NULL,