* Byungchul Park <[email protected]> wrote:
> diff --git a/kernel/locking/semaphore.c b/kernel/locking/semaphore.c
> index b8120ab..6634b68 100644
> --- a/kernel/locking/semaphore.c
> +++ b/kernel/locking/semaphore.c
> @@ -130,13 +130,14 @@ EXPORT_SYMBOL(down_killable);
> int down_trylock(struct semaphore *sem)
> {
> unsigned long flags;
> - int count;
> + int count = -1;
>
> - raw_spin_lock_irqsave(&sem->lock, flags);
> - count = sem->count - 1;
> - if (likely(count >= 0))
> - sem->count = count;
> - raw_spin_unlock_irqrestore(&sem->lock, flags);
> + if (raw_spin_trylock_irqsave(&sem->lock, flags)) {
> + count = sem->count - 1;
> + if (likely(count >= 0))
> + sem->count = count;
> + raw_spin_unlock_irqrestore(&sem->lock, flags);
> + }
I still don't really like it: two parallel trylocks will cause one of them to
fail
- while with the previous code they would both succeed.
None of these changes are necessary with all the printk robustification
changes/enhancements we talked about, right?
Thanks,
Ingo
