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Date:   Wed, 21 Dec 2022 13:18:10 +0800
From:   Vernon Yang <vernon2gm@gmail.com>
To:     Liam Howlett <liam.howlett@oracle.com>
Cc:     "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 8/8] maple_tree: refine mab_calc_split function
Message-ID: <Y6KWzfPrFIBh8kAj@vernon-pc>
References: <20221220142606.1698836-2-vernon2gm@gmail.com>
 <20221220142606.1698836-9-vernon2gm@gmail.com>
 <20221220150550.y5kknqwjc7q5bv75@revolver>
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On Tue, Dec 20, 2022 at 03:05:52PM +0000, Liam Howlett wrote:
> * Vernon Yang <vernon2gm@gmail.com> [221220 09:26]:
> > Invert the conditional judgment of the mid_split, to focus
> > the return statement in the last statement, which is easier
> > to understand and for better readability.
> >
> > Signed-off-by: Vernon Yang <vernon2gm@gmail.com>
> > ---
> >  lib/maple_tree.c | 5 ++---
> >  1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> > index 16cdcf309e97..d147669fb99c 100644
> > --- a/lib/maple_tree.c
> > +++ b/lib/maple_tree.c
> > @@ -1882,10 +1882,9 @@ static inline int mab_calc_split(struct ma_state *mas,
> >
> >  	/* Avoid ending a node on a NULL entry */
> >  	split = mab_no_null_split(bn, split, slot_count);
> > -	if (!(*mid_split))
> > -		return split;
> >
> > -	*mid_split = mab_no_null_split(bn, *mid_split, slot_count);
> > +	if (*mid_split)
> > +		*mid_split = mab_no_null_split(bn, *mid_split, slot_count);
>
> The function is written this way because mid_split is almost always
> zero.  If you want to change this, then we should add an unlikely() to
> the if statement.
Okay，thank you very much for the suggestion, I will add
an unlikely() to the if statement.

>
> >
> >  	return split;
> >  }
> > --
> > 2.34.1
> >
> >