On Mon, Feb 10, 2025 at 09:51:42AM -0500, Liam R. Howlett wrote:
> * I Hsin Cheng <richard120310@xxxxxxxxx> [250210 03:35]:
>
> > In mte_dead_node(), it already assign "node" as "mte_to_node(enode)" in
> > the first place, calling "mte_parent(enode)" will result in the same
> > "mte_to_node(enode)" again which is redundant.
>
> This is a very confusing way of saying "avoid calling mte_to_node() in
> the mte_parent() call by using the ma_dead_node() instead."
>
> In fact, the subject is wrong as well, since the mte_to_node() was
> removed from the call path of mte_dead_node(), and not the function
> itself.
>
> >
> > Refactor mte_dead_node() and utilize ma_dead_node() to perform the
> > parent check without the redundant "mte_to_node()".
> >
> > Signed-off-by: I Hsin Cheng <richard120310@xxxxxxxxx>
>
> The code looks right, but the subject and change log are not. Please
> respin the patch, something like this:
>
> maple_tree: Use ma_dead_node() in mte_dead_node()
>
> Using ma_dead_node() in mte_dead_node() avoids decoding the maple enode
> for a second time to find the parent.
>
> Feel free to change it as you'd like, but I couldn't follow what you
> meant.
>
> > ---
> > lib/maple_tree.c | 7 ++-----
> > 1 file changed, 2 insertions(+), 5 deletions(-)
> >
> > diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> > index f7153ade1be5..362f85c62678 100644
> > --- a/lib/maple_tree.c
> > +++ b/lib/maple_tree.c
> > @@ -584,13 +584,10 @@ static __always_inline bool ma_dead_node(const struct maple_node *node)
> > */
> > static __always_inline bool mte_dead_node(const struct maple_enode *enode)
> > {
> > - struct maple_node *parent, *node;
> > + struct maple_node *node;
> >
> > node = mte_to_node(enode);
> > - /* Do not reorder reads from the node prior to the parent check */
> > - smp_rmb();
> > - parent = mte_parent(enode);
> > - return (parent == node);
> > + return ma_dead_node(node);
> > }
> >
> > /*
> > --
> > 2.43.0
> >
Hello Liam,
Thanks for your kindly review!
> In fact, the subject is wrong as well, since the mte_to_node() was
> removed from the call path of mte_dead_node(), and not the function
> itself.
I see, I'll rephrase the whole commit and send a new patch later, what I
wrote is indeed too confusing. Thank you.
Best regards,
I Hsin Cheng
