[PATCH 0/2] Following cleanup after introduce mas_wr_store_type()

[PATCH 0/2] Following cleanup after introduce mas_wr_store_type()

[Wei Yang]

Here is two cleanup after introduction of mas_wr_store_type().

Patch 1 postpone new_end calculation when needed.

Patch 2 remove a unnecessary sanity check in mas_wr_slot_store().

Wei Yang (2):
  maple_tree: calculate new_end when needed
  maple_tree: remove sanity check from mas_wr_slot_store()

 lib/maple_tree.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

-- 
2.34.1

[PATCH 1/2] maple_tree: calculate new_end when needed

[Wei Yang]

For wr_exact_fit/wr_new_root, we don't need to calculate new_end.

Let's postpone it until necessary.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Liam R. Howlett <Liam.Howlett@Oracle.com>
CC: Sidhartha Kumar <sidhartha.kumar@oracle.com>
CC: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
 lib/maple_tree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 61de8f1daee8..f2628e3f3efc 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4122,7 +4122,6 @@ static inline void mas_wr_store_type(struct ma_wr_state *wr_mas)
 	if (!wr_mas->entry)
 		mas_wr_extend_null(wr_mas);
 
-	new_end = mas_wr_new_end(wr_mas);
 	if ((wr_mas->r_min == mas->index) && (wr_mas->r_max == mas->last)) {
 		mas->store_type = wr_exact_fit;
 		return;
@@ -4133,6 +4132,7 @@ static inline void mas_wr_store_type(struct ma_wr_state *wr_mas)
 		return;
 	}
 
+	new_end = mas_wr_new_end(wr_mas);
 	/* Potential spanning rebalance collapsing a node */
 	if (new_end < mt_min_slots[wr_mas->type]) {
 		if (!mte_is_root(mas->node)) {
-- 
2.34.1

[PATCH 2/2] maple_tree: remove sanity check from mas_wr_slot_store()

[Wei Yang]

After commit 5d659bbb52a2 ("maple_tree: introduce mas_wr_store_type()"),
the check here is redundant.

Let's remove it.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Liam R. Howlett <Liam.Howlett@Oracle.com>
CC: Sidhartha Kumar <sidhartha.kumar@oracle.com>
CC: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
 lib/maple_tree.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index f2628e3f3efc..5dfc589a8cde 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3810,7 +3810,7 @@ static inline void mas_wr_slot_store(struct ma_wr_state *wr_mas)
 			wr_mas->pivots[offset] = mas->index - 1;
 			mas->offset++; /* Keep mas accurate. */
 		}
-	} else if (!mt_in_rcu(mas->tree)) {
+	} else {
 		/*
 		 * Expand the range, only partially overwriting the previous and
 		 * next ranges
@@ -3820,8 +3820,6 @@ static inline void mas_wr_slot_store(struct ma_wr_state *wr_mas)
 		wr_mas->pivots[offset] = mas->index - 1;
 		wr_mas->pivots[offset + 1] = mas->last;
 		mas->offset++; /* Keep mas accurate. */
-	} else {
-		return;
 	}
 
 	trace_ma_write(__func__, mas, 0, wr_mas->entry);
-- 
2.34.1

Re: [PATCH 1/2] maple_tree: calculate new_end when needed

[Sid Kumar]

On 10/15/24 8:22 PM, Wei Yang wrote:
> For wr_exact_fit/wr_new_root, we don't need to calculate new_end.
>
> Let's postpone it until necessary.
>
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> CC: Liam R. Howlett <Liam.Howlett@Oracle.com>
> CC: Sidhartha Kumar <sidhartha.kumar@oracle.com>
> CC: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> ---
>   lib/maple_tree.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 61de8f1daee8..f2628e3f3efc 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -4122,7 +4122,6 @@ static inline void mas_wr_store_type(struct ma_wr_state *wr_mas)
>   	if (!wr_mas->entry)
>   		mas_wr_extend_null(wr_mas);
>   
> -	new_end = mas_wr_new_end(wr_mas);
>   	if ((wr_mas->r_min == mas->index) && (wr_mas->r_max == mas->last)) {
>   		mas->store_type = wr_exact_fit;
>   		return;
> @@ -4133,6 +4132,7 @@ static inline void mas_wr_store_type(struct ma_wr_state *wr_mas)
>   		return;
>   	}
>   
> +	new_end = mas_wr_new_end(wr_mas);
>   	/* Potential spanning rebalance collapsing a node */
>   	if (new_end < mt_min_slots[wr_mas->type]) {
>   		if (!mte_is_root(mas->node)) {

Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>

Re: [PATCH 2/2] maple_tree: remove sanity check from mas_wr_slot_store()

[Sid Kumar]

On 10/15/24 8:22 PM, Wei Yang wrote:
> After commit 5d659bbb52a2 ("maple_tree: introduce mas_wr_store_type()"),
> the check here is redundant.
>
> Let's remove it.
>
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> CC: Liam R. Howlett <Liam.Howlett@Oracle.com>
> CC: Sidhartha Kumar <sidhartha.kumar@oracle.com>
> CC: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> ---
>   lib/maple_tree.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index f2628e3f3efc..5dfc589a8cde 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -3810,7 +3810,7 @@ static inline void mas_wr_slot_store(struct ma_wr_state *wr_mas)
>   			wr_mas->pivots[offset] = mas->index - 1;
>   			mas->offset++; /* Keep mas accurate. */
>   		}
> -	} else if (!mt_in_rcu(mas->tree)) {


This means ((new_end == mas->end) && (!mt_in_rcu(mas->tree)) must be 
true so we know we are not in rcu mode at this point. So this makes sense

> +	} else {
>   		/*
>   		 * Expand the range, only partially overwriting the previous and
>   		 * next ranges
> @@ -3820,8 +3820,6 @@ static inline void mas_wr_slot_store(struct ma_wr_state *wr_mas)
>   		wr_mas->pivots[offset] = mas->index - 1;
>   		wr_mas->pivots[offset + 1] = mas->last;
>   		mas->offset++; /* Keep mas accurate. */
> -	} else {
> -		return;
>   	}
>   
>   	trace_ma_write(__func__, mas, 0, wr_mas->entry);

Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>

Re: [PATCH 1/2] maple_tree: calculate new_end when needed

[Liam R. Howlett]

* Wei Yang <richard.weiyang@gmail.com> [241015 20:22]:
> For wr_exact_fit/wr_new_root, we don't need to calculate new_end.
> 
> Let's postpone it until necessary.
> 
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> CC: Liam R. Howlett <Liam.Howlett@Oracle.com>
> CC: Sidhartha Kumar <sidhartha.kumar@oracle.com>
> CC: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

Too bad these were missed in the review of the patches.

Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

> ---
>  lib/maple_tree.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 61de8f1daee8..f2628e3f3efc 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -4122,7 +4122,6 @@ static inline void mas_wr_store_type(struct ma_wr_state *wr_mas)
>  	if (!wr_mas->entry)
>  		mas_wr_extend_null(wr_mas);
>  
> -	new_end = mas_wr_new_end(wr_mas);
>  	if ((wr_mas->r_min == mas->index) && (wr_mas->r_max == mas->last)) {
>  		mas->store_type = wr_exact_fit;
>  		return;
> @@ -4133,6 +4132,7 @@ static inline void mas_wr_store_type(struct ma_wr_state *wr_mas)
>  		return;
>  	}
>  
> +	new_end = mas_wr_new_end(wr_mas);
>  	/* Potential spanning rebalance collapsing a node */
>  	if (new_end < mt_min_slots[wr_mas->type]) {
>  		if (!mte_is_root(mas->node)) {
> -- 
> 2.34.1
> 

Re: [PATCH 2/2] maple_tree: remove sanity check from mas_wr_slot_store()

[Liam R. Howlett]

* Wei Yang <richard.weiyang@gmail.com> [241015 20:22]:
> After commit 5d659bbb52a2 ("maple_tree: introduce mas_wr_store_type()"),
> the check here is redundant.
> 
> Let's remove it.
> 
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> CC: Liam R. Howlett <Liam.Howlett@Oracle.com>
> CC: Sidhartha Kumar <sidhartha.kumar@oracle.com>
> CC: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> ---
>  lib/maple_tree.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index f2628e3f3efc..5dfc589a8cde 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -3810,7 +3810,7 @@ static inline void mas_wr_slot_store(struct ma_wr_state *wr_mas)
>  			wr_mas->pivots[offset] = mas->index - 1;
>  			mas->offset++; /* Keep mas accurate. */
>  		}
> -	} else if (!mt_in_rcu(mas->tree)) {
> +	} else {

It would be worth adding a WARN_ON_ONCE() in here in case something
changes in the code paths.

>  		/*
>  		 * Expand the range, only partially overwriting the previous and
>  		 * next ranges
> @@ -3820,8 +3820,6 @@ static inline void mas_wr_slot_store(struct ma_wr_state *wr_mas)
>  		wr_mas->pivots[offset] = mas->index - 1;
>  		wr_mas->pivots[offset + 1] = mas->last;
>  		mas->offset++; /* Keep mas accurate. */
> -	} else {
> -		return;
>  	}
>  
>  	trace_ma_write(__func__, mas, 0, wr_mas->entry);
> -- 
> 2.34.1
>