Re: [PATCH] locktorture: Add raw_spinlock* torture tests for PREEMPT_RT kernels
From: Paul E. McKenney
Date: Sat Feb 18 2023 - 14:36:19 EST
On Wed, Feb 15, 2023 at 02:10:35PM +0800, Zqiang wrote:
> For PREEMPT_RT kernel, the spin_lock, spin_lock_irq will converted
> to sleepable rt_spin_lock and the interrupt related suffix for
> spin_lock/unlock(_irq, irqsave/irqrestore) do not affect CPU's
> interrupt state. this commit therefore add raw_spin_lock torture
> tests, this is a strict spin lock implementation in RT kernels.
>
> Signed-off-by: Zqiang <qiang1.zhang@xxxxxxxxx>
A nice addition! Is this something you will be testing regularly?
If not, should there be additional locktorture scenarios, perhaps prefixed
by "RT-" to hint that they are not normally available?
Or did you have some other plan for making use of these?
Thanx, Paul
> ---
> kernel/locking/locktorture.c | 58 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 58 insertions(+)
>
> diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
> index 9425aff08936..521197366f27 100644
> --- a/kernel/locking/locktorture.c
> +++ b/kernel/locking/locktorture.c
> @@ -257,6 +257,61 @@ static struct lock_torture_ops spin_lock_irq_ops = {
> .name = "spin_lock_irq"
> };
>
> +#ifdef CONFIG_PREEMPT_RT
> +static DEFINE_RAW_SPINLOCK(torture_raw_spinlock);
> +
> +static int torture_raw_spin_lock_write_lock(int tid __maybe_unused)
> +__acquires(torture_raw_spinlock)
> +{
> + raw_spin_lock(&torture_raw_spinlock);
> + return 0;
> +}
> +
> +static void torture_raw_spin_lock_write_unlock(int tid __maybe_unused)
> +__releases(torture_raw_spinlock)
> +{
> + raw_spin_unlock(&torture_raw_spinlock);
> +}
> +
> +static struct lock_torture_ops raw_spin_lock_ops = {
> + .writelock = torture_raw_spin_lock_write_lock,
> + .write_delay = torture_spin_lock_write_delay,
> + .task_boost = torture_rt_boost,
> + .writeunlock = torture_raw_spin_lock_write_unlock,
> + .readlock = NULL,
> + .read_delay = NULL,
> + .readunlock = NULL,
> + .name = "raw_spin_lock"
> +};
> +
> +static int torture_raw_spin_lock_write_lock_irq(int tid __maybe_unused)
> +__acquires(torture_raw_spinlock)
> +{
> + unsigned long flags;
> +
> + raw_spin_lock_irqsave(&torture_raw_spinlock, flags);
> + cxt.cur_ops->flags = flags;
> + return 0;
> +}
> +
> +static void torture_raw_spin_lock_write_unlock_irq(int tid __maybe_unused)
> +__releases(torture_raw_spinlock)
> +{
> + raw_spin_unlock_irqrestore(&torture_raw_spinlock, cxt.cur_ops->flags);
> +}
> +
> +static struct lock_torture_ops raw_spin_lock_irq_ops = {
> + .writelock = torture_raw_spin_lock_write_lock_irq,
> + .write_delay = torture_spin_lock_write_delay,
> + .task_boost = torture_rt_boost,
> + .writeunlock = torture_raw_spin_lock_write_unlock_irq,
> + .readlock = NULL,
> + .read_delay = NULL,
> + .readunlock = NULL,
> + .name = "raw_spin_lock_irq"
> +};
> +#endif
> +
> static DEFINE_RWLOCK(torture_rwlock);
>
> static int torture_rwlock_write_lock(int tid __maybe_unused)
> @@ -1017,6 +1072,9 @@ static int __init lock_torture_init(void)
> static struct lock_torture_ops *torture_ops[] = {
> &lock_busted_ops,
> &spin_lock_ops, &spin_lock_irq_ops,
> +#ifdef CONFIG_PREEMPT_RT
> + &raw_spin_lock_ops, &raw_spin_lock_irq_ops,
> +#endif
> &rw_lock_ops, &rw_lock_irq_ops,
> &mutex_lock_ops,
> &ww_mutex_lock_ops,
> --
> 2.25.1
>