[PATCH] maple_tree: Mark three functions as __maybe_unused

[PATCH] maple_tree: Mark three functions as __maybe_unused

[Liam R. Howlett]

People keep trying to remove three functions that are going to be used
in a feature that is being developed.  Dropping the functions entirely
may end up with people trying to use the bit for other uses, as people
have tried in the past.

Adding __maybe_unused stops compilers complaining about the unused
functions so they can be silently optimised out of the compiled code and
people won't try to claim the bit for another use.

Link: https://lore.kernel.org/all/20230726080916.17454-2-zhangpeng.00@bytedance.com/
Link: https://lore.kernel.org/all/202408310728.S7EE59BN-lkp@intel.com/
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---
 lib/maple_tree.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 4f34e50c92b5..20990ecba2dd 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -348,17 +348,17 @@ static inline void *mte_safe_root(const struct maple_enode *node)
 	return (void *)((unsigned long)node & ~MAPLE_ROOT_NODE);
 }
 
-static inline void *mte_set_full(const struct maple_enode *node)
+static inline void __maybe_unused *mte_set_full(const struct maple_enode *node)
 {
 	return (void *)((unsigned long)node & ~MAPLE_ENODE_NULL);
 }
 
-static inline void *mte_clear_full(const struct maple_enode *node)
+static inline void __maybe_unused *mte_clear_full(const struct maple_enode *node)
 {
 	return (void *)((unsigned long)node | MAPLE_ENODE_NULL);
 }
 
-static inline bool mte_has_null(const struct maple_enode *node)
+static inline bool __maybe_unused mte_has_null(const struct maple_enode *node)
 {
 	return (unsigned long)node & MAPLE_ENODE_NULL;
 }
-- 
2.43.0

Re: [PATCH] maple_tree: Mark three functions as __maybe_unused

[Lorenzo Stoakes]

On Fri, Sep 06, 2024 at 10:15:06PM GMT, Liam R. Howlett wrote:
> People keep trying to remove three functions that are going to be used
> in a feature that is being developed.  Dropping the functions entirely
> may end up with people trying to use the bit for other uses, as people
> have tried in the past.
>
> Adding __maybe_unused stops compilers complaining about the unused
> functions so they can be silently optimised out of the compiled code and
> people won't try to claim the bit for another use.
>
> Link: https://lore.kernel.org/all/20230726080916.17454-2-zhangpeng.00@bytedance.com/
> Link: https://lore.kernel.org/all/202408310728.S7EE59BN-lkp@intel.com/
> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>

Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

> ---
>  lib/maple_tree.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 4f34e50c92b5..20990ecba2dd 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -348,17 +348,17 @@ static inline void *mte_safe_root(const struct maple_enode *node)
>  	return (void *)((unsigned long)node & ~MAPLE_ROOT_NODE);
>  }
>
> -static inline void *mte_set_full(const struct maple_enode *node)
> +static inline void __maybe_unused *mte_set_full(const struct maple_enode *node)
>  {
>  	return (void *)((unsigned long)node & ~MAPLE_ENODE_NULL);
>  }
>
> -static inline void *mte_clear_full(const struct maple_enode *node)
> +static inline void __maybe_unused *mte_clear_full(const struct maple_enode *node)
>  {
>  	return (void *)((unsigned long)node | MAPLE_ENODE_NULL);
>  }
>
> -static inline bool mte_has_null(const struct maple_enode *node)
> +static inline bool __maybe_unused mte_has_null(const struct maple_enode *node)
>  {
>  	return (unsigned long)node & MAPLE_ENODE_NULL;
>  }
> --
> 2.43.0
>

Re: [PATCH] maple_tree: Mark three functions as __maybe_unused

[Kuan-Wei Chiu]

On Sat, Sep 07, 2024 at 07:31:14PM +0100, Lorenzo Stoakes wrote:
> On Fri, Sep 06, 2024 at 10:15:06PM GMT, Liam R. Howlett wrote:
> > People keep trying to remove three functions that are going to be used
> > in a feature that is being developed.  Dropping the functions entirely
> > may end up with people trying to use the bit for other uses, as people
> > have tried in the past.
> >
> > Adding __maybe_unused stops compilers complaining about the unused
> > functions so they can be silently optimised out of the compiled code and
> > people won't try to claim the bit for another use.
> >
> > Link: https://lore.kernel.org/all/20230726080916.17454-2-zhangpeng.00@bytedance.com/
> > Link: https://lore.kernel.org/all/202408310728.S7EE59BN-lkp@intel.com/
> > Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> 
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

Thank you for solving the compilation warning!

Reviewed-by: Kuan-Wei Chiu <visitorckw@gmail.com>

Regards,
Kuan-Wei
> 
> > ---
> >  lib/maple_tree.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> > index 4f34e50c92b5..20990ecba2dd 100644
> > --- a/lib/maple_tree.c
> > +++ b/lib/maple_tree.c
> > @@ -348,17 +348,17 @@ static inline void *mte_safe_root(const struct maple_enode *node)
> >  	return (void *)((unsigned long)node & ~MAPLE_ROOT_NODE);
> >  }
> >
> > -static inline void *mte_set_full(const struct maple_enode *node)
> > +static inline void __maybe_unused *mte_set_full(const struct maple_enode *node)
> >  {
> >  	return (void *)((unsigned long)node & ~MAPLE_ENODE_NULL);
> >  }
> >
> > -static inline void *mte_clear_full(const struct maple_enode *node)
> > +static inline void __maybe_unused *mte_clear_full(const struct maple_enode *node)
> >  {
> >  	return (void *)((unsigned long)node | MAPLE_ENODE_NULL);
> >  }
> >
> > -static inline bool mte_has_null(const struct maple_enode *node)
> > +static inline bool __maybe_unused mte_has_null(const struct maple_enode *node)
> >  {
> >  	return (unsigned long)node & MAPLE_ENODE_NULL;
> >  }
> > --
> > 2.43.0
> >
>