Re: [PATCH] maple_tree: remove conditionals to detect wr_node_store

[Liam R. Howlett]

* Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx> [241009 11:20]:
> From: Sidhartha <sidhartha.kumar@xxxxxxxxxx>
> 
> In mas_wr_store_type(), we check if new_end < mt_slots[wr_mas->type]. If
> this check fails, we know that ,after this, new_end is >= mt_min_slots.
> Checking this again when we detect a wr_node_store later in the function
> is reduntant. Because this check is part of an OR statement, the statement
> will always evaluate to true, therefore we can just get rid of it.
> 
> Suggested-by; Wei Yang <richard.weiyang@xxxxxxxxx>
> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
> ---
>  lib/maple_tree.c | 9 +--------
>  1 file changed, 1 insertion(+), 8 deletions(-)
> 
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 4b423330d83c..f5a12d37b352 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -4252,14 +4252,7 @@ static inline void mas_wr_store_type(struct ma_wr_state *wr_mas)
>  		return;
>  	}
>  
> -	if (mte_is_root(mas->node) || (new_end >= mt_min_slots[wr_mas->type]) ||
> -		(mas->mas_flags & MA_STATE_BULK)) {

Although this will be evaluated as true due to the new_end having at
least the minimum data, it points out that MA_STATE_BULK is not being
evaluated correctly in the new_end < min case.

That is, we will rebalance if we are in MA_STATE_BULK mode without
meeting the sufficient data mark - which is not correct.

> -		mas->store_type = wr_node_store;
> -		return;
> -	}
> -
> -	mas->store_type = wr_invalid;
> -	MAS_WARN_ON(mas, 1);
> +	mas->store_type = wr_node_store;
>  }
>  
>  /**
> -- 
> 2.43.0
>