On Thu, 22 Aug 2024, Christian Brauner wrote:
> Port the __I_LRU_ISOLATING mechanism to use the new var event mechanism.
>
> Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
> ---
> fs/inode.c | 26 +++++++++++++++++---------
> 1 file changed, 17 insertions(+), 9 deletions(-)
>
> diff --git a/fs/inode.c b/fs/inode.c
> index d18e1567c487..c8a5c63dc980 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -510,8 +510,7 @@ static void inode_unpin_lru_isolating(struct inode *inode)
> spin_lock(&inode->i_lock);
> WARN_ON(!(inode->i_state & I_LRU_ISOLATING));
> inode->i_state &= ~I_LRU_ISOLATING;
> - smp_mb();
> - wake_up_bit(&inode->i_state, __I_LRU_ISOLATING);
> + inode_wake_up_bit(inode, __I_LRU_ISOLATING);
> spin_unlock(&inode->i_lock);
> }
>
> @@ -519,13 +518,22 @@ static void inode_wait_for_lru_isolating(struct inode *inode)
> {
> lockdep_assert_held(&inode->i_lock);
> if (inode->i_state & I_LRU_ISOLATING) {
> - DEFINE_WAIT_BIT(wq, &inode->i_state, __I_LRU_ISOLATING);
> - wait_queue_head_t *wqh;
> -
> - wqh = bit_waitqueue(&inode->i_state, __I_LRU_ISOLATING);
> - spin_unlock(&inode->i_lock);
> - __wait_on_bit(wqh, &wq, bit_wait, TASK_UNINTERRUPTIBLE);
> - spin_lock(&inode->i_lock);
> + struct wait_bit_queue_entry wqe;
> + struct wait_queue_head *wq_head;
> +
> + wq_head = inode_bit_waitqueue(&wqe, inode, __I_LRU_ISOLATING);
> + for (;;) {
> + prepare_to_wait_event(wq_head, &wqe.wq_entry,
> + TASK_UNINTERRUPTIBLE);
> + if (inode->i_state & I_LRU_ISOLATING) {
> + spin_unlock(&inode->i_lock);
> + schedule();
> + spin_lock(&inode->i_lock);
> + continue;
> + }
> + break;
> + }
> + finish_wait(wq_head, &wqe.wq_entry);
I would really like to add
wait_var_event_locked(variable, conditon, spinlock)
so that above would be one or two lines.
#define wait_var_event_locked(var, condition, lock) \
do { \
might_sleep(); \
if (condition) \
break; \
___wait_var_event(var, condition, TASK_UNINTERRUPTIBLE, \
0, 0, \
spin_unlock(lock);schedule();spin_lock(lock)); \
} while(0)
That can happen after you series lands though.
The wake_up here don't need a memory barrier either.
NeilBrown
> WARN_ON(inode->i_state & I_LRU_ISOLATING);
> }
> }
>
> --
> 2.43.0
>
>
