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locktorture: Add readers_bind and writers_bind module parameters

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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: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
This commit is contained in:
Paul E. McKenney 2023-07-27 20:04:06 -07:00 committed by Frederic Weisbecker
parent 0cfecd7d75
commit 73e3412424
1 changed files with 62 additions and 2 deletions
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64
kernel/locking/locktorture.c
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@ -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,