On 21.11.18 г. 21:09 ч., Josef Bacik wrote:
> The cleaner thread usually takes care of delayed iputs, with the
> exception of the btrfs_end_transaction_throttle path. The cleaner
> thread only gets woken up every 30 seconds, so instead wake it up to do
> it's work so that we can free up that space as quickly as possible.
Have you done any measurements how this affects the overall system. I
suspect this introduces a lot of noise since now we are going to be
doing a thread wakeup on every iput, does this give a chance to have
nice, large batches of iputs that the cost of wake up can be amortized
across?
>
> Reviewed-by: Filipe Manana <fdman...@suse.com>
> Signed-off-by: Josef Bacik <jo...@toxicpanda.com>
> ---
> fs/btrfs/inode.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 3da9ac463344..3c42d8887183 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -3264,6 +3264,7 @@ void btrfs_add_delayed_iput(struct inode *inode)
> ASSERT(list_empty(&binode->delayed_iput));
> list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
> spin_unlock(&fs_info->delayed_iput_lock);
> + wake_up_process(fs_info->cleaner_kthread);
> }
>
> void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
>
