On Fri, Dec 09, 2022 at 02:23:04AM +0000, Joel Fernandes (Google) wrote:
> Currently RT boosting is only done for rtmutex_lock, however with proxy
> execution, we also have the mutex_lock participating in priorities. To
> exercise the testing better, add RT boosting to other lock testing types
> as well, using a new knob (rt_boost).
>
> Tested with boot parameters:
> locktorture.torture_type=mutex_lock
> locktorture.onoff_interval=1
> locktorture.nwriters_stress=8
> locktorture.stutter=0
> locktorture.rt_boost=1
> locktorture.rt_boost_factor=1
> locktorture.nlocks=3
>
> For the rtmutex test, rt_boost is always enabled even if disabling is
> requested.
>
> Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
Nice, thank you!
Except that "git am -3" doesn't know about the commit on which this
is based. Could you please rebase onto the -rcu tree's "dev" branch?
Though there is nothing touching kernel/locking/locktorture.c in
-rcu at the moment, so I confess some curiosity as to exactly what
these patches are based on. ;-)
Thanx, Paul
> ---
> kernel/locking/locktorture.c | 99 ++++++++++++++++++++----------------
> 1 file changed, 56 insertions(+), 43 deletions(-)
>
> diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
> index bc3557677eed..8968fd65a90d 100644
> --- a/kernel/locking/locktorture.c
> +++ b/kernel/locking/locktorture.c
> @@ -46,6 +46,8 @@ torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable.");
> torture_param(int, stat_interval, 60,
> "Number of seconds between stats printk()s");
> torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
> +torture_param(int, rt_boost, 2,
> + "Do periodic rt-boost. 0=Disable, 1=Only for rt_mutex, 2=For all lock types.");
> torture_param(int, verbose, 1,
> "Enable verbose debugging printk()s");
> torture_param(int, nlocks, 1,
> @@ -129,15 +131,49 @@ static void torture_lock_busted_write_unlock(int tid __maybe_unused)
> /* BUGGY, do not use in real life!!! */
> }
>
> -static void torture_boost_dummy(struct torture_random_state *trsp)
> +static void __torture_rt_boost(struct torture_random_state *trsp)
> {
> - /* Only rtmutexes care about priority */
> + const unsigned int factor = 50000; /* yes, quite arbitrary */
> +
> + if (!rt_task(current)) {
> + /*
> + * Boost priority once every ~50k operations. When the
> + * task tries to take the lock, the rtmutex it will account
> + * for the new priority, and do any corresponding pi-dance.
> + */
> + if (trsp && !(torture_random(trsp) %
> + (cxt.nrealwriters_stress * factor))) {
> + sched_set_fifo(current);
> + } else /* common case, do nothing */
> + return;
> + } else {
> + /*
> + * The task will remain boosted for another ~500k operations,
> + * then restored back to its original prio, and so forth.
> + *
> + * When @trsp is nil, we want to force-reset the task for
> + * stopping the kthread.
> + */
> + if (!trsp || !(torture_random(trsp) %
> + (cxt.nrealwriters_stress * factor * 2))) {
> + sched_set_normal(current, 0);
> + } else /* common case, do nothing */
> + return;
> + }
> +}
> +
> +static void torture_rt_boost(struct torture_random_state *trsp)
> +{
> + if (rt_boost != 2)
> + return;
> +
> + __torture_rt_boost(trsp);
> }
>
> static struct lock_torture_ops lock_busted_ops = {
> .writelock = torture_lock_busted_write_lock,
> .write_delay = torture_lock_busted_write_delay,
> - .task_boost = torture_boost_dummy,
> + .task_boost = torture_rt_boost,
> .writeunlock = torture_lock_busted_write_unlock,
> .readlock = NULL,
> .read_delay = NULL,
> @@ -181,7 +217,7 @@ __releases(torture_spinlock)
> static struct lock_torture_ops spin_lock_ops = {
> .writelock = torture_spin_lock_write_lock,
> .write_delay = torture_spin_lock_write_delay,
> - .task_boost = torture_boost_dummy,
> + .task_boost = torture_rt_boost,
> .writeunlock = torture_spin_lock_write_unlock,
> .readlock = NULL,
> .read_delay = NULL,
> @@ -208,7 +244,7 @@ __releases(torture_spinlock)
> static struct lock_torture_ops spin_lock_irq_ops = {
> .writelock = torture_spin_lock_write_lock_irq,
> .write_delay = torture_spin_lock_write_delay,
> - .task_boost = torture_boost_dummy,
> + .task_boost = torture_rt_boost,
> .writeunlock = torture_lock_spin_write_unlock_irq,
> .readlock = NULL,
> .read_delay = NULL,
> @@ -277,7 +313,7 @@ __releases(torture_rwlock)
> static struct lock_torture_ops rw_lock_ops = {
> .writelock = torture_rwlock_write_lock,
> .write_delay = torture_rwlock_write_delay,
> - .task_boost = torture_boost_dummy,
> + .task_boost = torture_rt_boost,
> .writeunlock = torture_rwlock_write_unlock,
> .readlock = torture_rwlock_read_lock,
> .read_delay = torture_rwlock_read_delay,
> @@ -320,7 +356,7 @@ __releases(torture_rwlock)
> static struct lock_torture_ops rw_lock_irq_ops = {
> .writelock = torture_rwlock_write_lock_irq,
> .write_delay = torture_rwlock_write_delay,
> - .task_boost = torture_boost_dummy,
> + .task_boost = torture_rt_boost,
> .writeunlock = torture_rwlock_write_unlock_irq,
> .readlock = torture_rwlock_read_lock_irq,
> .read_delay = torture_rwlock_read_delay,
> @@ -362,7 +398,7 @@ __releases(torture_mutex)
> static struct lock_torture_ops mutex_lock_ops = {
> .writelock = torture_mutex_lock,
> .write_delay = torture_mutex_delay,
> - .task_boost = torture_boost_dummy,
> + .task_boost = torture_rt_boost,
> .writeunlock = torture_mutex_unlock,
> .readlock = NULL,
> .read_delay = NULL,
> @@ -460,7 +496,7 @@ static struct lock_torture_ops ww_mutex_lock_ops = {
> .exit = torture_ww_mutex_exit,
> .writelock = torture_ww_mutex_lock,
> .write_delay = torture_mutex_delay,
> - .task_boost = torture_boost_dummy,
> + .task_boost = torture_rt_boost,
> .writeunlock = torture_ww_mutex_unlock,
> .readlock = NULL,
> .read_delay = NULL,
> @@ -478,37 +514,6 @@ __acquires(torture_rtmutex)
> return 0;
> }
>
> -static void torture_rtmutex_boost(struct torture_random_state *trsp)
> -{
> - const unsigned int factor = 50000; /* yes, quite arbitrary */
> -
> - if (!rt_task(current)) {
> - /*
> - * Boost priority once every ~50k operations. When the
> - * task tries to take the lock, the rtmutex it will account
> - * for the new priority, and do any corresponding pi-dance.
> - */
> - if (trsp && !(torture_random(trsp) %
> - (cxt.nrealwriters_stress * factor))) {
> - sched_set_fifo(current);
> - } else /* common case, do nothing */
> - return;
> - } else {
> - /*
> - * The task will remain boosted for another ~500k operations,
> - * then restored back to its original prio, and so forth.
> - *
> - * When @trsp is nil, we want to force-reset the task for
> - * stopping the kthread.
> - */
> - if (!trsp || !(torture_random(trsp) %
> - (cxt.nrealwriters_stress * factor * 2))) {
> - sched_set_normal(current, 0);
> - } else /* common case, do nothing */
> - return;
> - }
> -}
> -
> static void torture_rtmutex_delay(struct torture_random_state *trsp)
> {
> const unsigned long shortdelay_us = 2;
> @@ -534,10 +539,18 @@ __releases(torture_rtmutex)
> rt_mutex_unlock(&torture_rtmutex);
> }
>
> +static void torture_rt_boost_rtmutex(struct torture_random_state *trsp)
> +{
> + if (!rt_boost)
> + return;
> +
> + __torture_rt_boost(trsp);
> +}
> +
> static struct lock_torture_ops rtmutex_lock_ops = {
> .writelock = torture_rtmutex_lock,
> .write_delay = torture_rtmutex_delay,
> - .task_boost = torture_rtmutex_boost,
> + .task_boost = torture_rt_boost_rtmutex,
> .writeunlock = torture_rtmutex_unlock,
> .readlock = NULL,
> .read_delay = NULL,
> @@ -604,7 +617,7 @@ __releases(torture_rwsem)
> static struct lock_torture_ops rwsem_lock_ops = {
> .writelock = torture_rwsem_down_write,
> .write_delay = torture_rwsem_write_delay,
> - .task_boost = torture_boost_dummy,
> + .task_boost = torture_rt_boost,
> .writeunlock = torture_rwsem_up_write,
> .readlock = torture_rwsem_down_read,
> .read_delay = torture_rwsem_read_delay,
> @@ -656,7 +669,7 @@ static struct lock_torture_ops percpu_rwsem_lock_ops = {
> .exit = torture_percpu_rwsem_exit,
> .writelock = torture_percpu_rwsem_down_write,
> .write_delay = torture_rwsem_write_delay,
> - .task_boost = torture_boost_dummy,
> + .task_boost = torture_rt_boost,
> .writeunlock = torture_percpu_rwsem_up_write,
> .readlock = torture_percpu_rwsem_down_read,
> .read_delay = torture_rwsem_read_delay,
> --
> 2.39.0.rc1.256.g54fd8350bd-goog
>
