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

[Liam R. Howlett]

* Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> [241009 20:02]:
> * 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.

Reading through this function, it would be much cleaner to return the
enum from the function and assign it in the caller.

> 
> > -		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
> > 
> 
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