diff mbox series

[v2,13/16] maple_tree: have mas_store() allocate nodes if needed

Message ID 20240607185257.963768-14-sidhartha.kumar@oracle.com (mailing list archive)
State New
Headers show
Series Introduce a store type enum for the Maple tree | expand

Commit Message

Sidhartha Kumar June 7, 2024, 6:52 p.m. UTC
Not all users of mas_store() enter with nodes already preallocated.
Check for the MA_STATE_PREALLOC flag to decide whether to preallocate nodes
within mas_store() rather than relying on future write helper functions
to perform the allocations. This allows the write helper functions to be
simplified as they do not have to do checks to make sure there are
enough allocated nodes to perform the write.

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
---
 lib/maple_tree.c | 32 ++++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

Comments

Liam R. Howlett June 13, 2024, 3 p.m. UTC | #1
* Sidhartha Kumar <sidhartha.kumar@oracle.com> [240607 14:53]:
> Not all users of mas_store() enter with nodes already preallocated.
> Check for the MA_STATE_PREALLOC flag to decide whether to preallocate nodes
> within mas_store() rather than relying on future write helper functions
> to perform the allocations. This allows the write helper functions to be
> simplified as they do not have to do checks to make sure there are
> enough allocated nodes to perform the write.
> 
> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
> ---
>  lib/maple_tree.c | 32 ++++++++++++++++++++++++++++----
>  1 file changed, 28 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 8b17768db5f2..92f133ea5f00 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -5528,6 +5528,20 @@ static inline void mte_destroy_walk(struct maple_enode *enode,
>  		mt_destroy_walk(enode, mt, true);
>  	}
>  }
> +
> +static inline void mas_wr_store_prealloc(struct ma_wr_state *wr_mas, void *entry)
> +{
> +	struct ma_state *mas = wr_mas->mas;
> +	int request;
> +
> +	mas_wr_prealloc_setup(wr_mas);
> +	mas_wr_store_type(wr_mas);
> +	request = mas_prealloc_calc(mas, entry);
> +	if (!request)
> +		return;
> +
> +	mas_node_count(mas, request);
> +}
>  /* Interface */
>  
>  /**
> @@ -5536,8 +5550,6 @@ static inline void mte_destroy_walk(struct maple_enode *enode,
>   * @entry: The entry to store.
>   *
>   * The @mas->index and @mas->last is used to set the range for the @entry.
> - * Note: The @mas should have pre-allocated entries to ensure there is memory to
> - * store the entry.  Please see mas_expected_entries()/mas_destroy() for more details.
>   *
>   * Return: the first entry between mas->index and mas->last or %NULL.
>   */
> @@ -5563,9 +5575,21 @@ void *mas_store(struct ma_state *mas, void *entry)
>  	 * want to examine what happens if a single store operation was to
>  	 * overwrite multiple entries within a self-balancing B-Tree.
>  	 */
> -	mas_wr_prealloc_setup(&wr_mas);
> -	mas_wr_store_type(&wr_mas);
> +	if (mas->mas_flags & MA_STATE_PREALLOC) {
> +		mas_wr_prealloc_setup(&wr_mas);
> +		mas_wr_store_type(&wr_mas);
> +		mas_wr_store_entry(&wr_mas);
> +		MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
> +		return wr_mas.content;
> +	}
> +
> +	mas_wr_store_prealloc(&wr_mas, entry);

Since this is the only place mas_wr_store_prealloc() is called and the
first two things it does is the same as the if() statement above, then
both calls can be moved outside of the if() statement.  That also means
the helper function is somewhat small, which makes it seem like it's
probably not worth having?  Maybe I missed something though?

> +	WARN_ON_ONCE(mas->store_type == wr_invalid);
> +	if (mas_is_err(mas))
> +		return NULL;
> +
>  	mas_wr_store_entry(&wr_mas);
> +	mas_destroy(mas);
>  	return wr_mas.content;
>  }
>  EXPORT_SYMBOL_GPL(mas_store);
> -- 
> 2.45.2
>
Sidhartha Kumar June 17, 2024, 9:18 p.m. UTC | #2
On 6/13/24 8:00 AM, Liam R. Howlett wrote:
> * Sidhartha Kumar <sidhartha.kumar@oracle.com> [240607 14:53]:
>> Not all users of mas_store() enter with nodes already preallocated.
>> Check for the MA_STATE_PREALLOC flag to decide whether to preallocate nodes
>> within mas_store() rather than relying on future write helper functions
>> to perform the allocations. This allows the write helper functions to be
>> simplified as they do not have to do checks to make sure there are
>> enough allocated nodes to perform the write.
>>
>> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
>> ---
>>   lib/maple_tree.c | 32 ++++++++++++++++++++++++++++----
>>   1 file changed, 28 insertions(+), 4 deletions(-)
>>
>> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
>> index 8b17768db5f2..92f133ea5f00 100644
>> --- a/lib/maple_tree.c
>> +++ b/lib/maple_tree.c
>> @@ -5528,6 +5528,20 @@ static inline void mte_destroy_walk(struct maple_enode *enode,
>>   		mt_destroy_walk(enode, mt, true);
>>   	}
>>   }
>> +
>> +static inline void mas_wr_store_prealloc(struct ma_wr_state *wr_mas, void *entry)
>> +{
>> +	struct ma_state *mas = wr_mas->mas;
>> +	int request;
>> +
>> +	mas_wr_prealloc_setup(wr_mas);
>> +	mas_wr_store_type(wr_mas);
>> +	request = mas_prealloc_calc(mas, entry);
>> +	if (!request)
>> +		return;
>> +
>> +	mas_node_count(mas, request);
>> +}
>>   /* Interface */
>>   
>>   /**
>> @@ -5536,8 +5550,6 @@ static inline void mte_destroy_walk(struct maple_enode *enode,
>>    * @entry: The entry to store.
>>    *
>>    * The @mas->index and @mas->last is used to set the range for the @entry.
>> - * Note: The @mas should have pre-allocated entries to ensure there is memory to
>> - * store the entry.  Please see mas_expected_entries()/mas_destroy() for more details.
>>    *
>>    * Return: the first entry between mas->index and mas->last or %NULL.
>>    */
>> @@ -5563,9 +5575,21 @@ void *mas_store(struct ma_state *mas, void *entry)
>>   	 * want to examine what happens if a single store operation was to
>>   	 * overwrite multiple entries within a self-balancing B-Tree.
>>   	 */
>> -	mas_wr_prealloc_setup(&wr_mas);
>> -	mas_wr_store_type(&wr_mas);
>> +	if (mas->mas_flags & MA_STATE_PREALLOC) {
>> +		mas_wr_prealloc_setup(&wr_mas);
>> +		mas_wr_store_type(&wr_mas);
>> +		mas_wr_store_entry(&wr_mas);
>> +		MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
>> +		return wr_mas.content;
>> +	}
>> +
>> +	mas_wr_store_prealloc(&wr_mas, entry);
> 
> Since this is the only place mas_wr_store_prealloc() is called and the
> first two things it does is the same as the if() statement above, then
> both calls can be moved outside of the if() statement.  That also means
> the helper function is somewhat small, which makes it seem like it's
> probably not worth having?  Maybe I missed something though?
> 

I agree the helper function is not needed, I'll refactor this without using 
another function.

Thanks,
Sid

>> +	WARN_ON_ONCE(mas->store_type == wr_invalid);
>> +	if (mas_is_err(mas))
>> +		return NULL;
>> +
>>   	mas_wr_store_entry(&wr_mas);
>> +	mas_destroy(mas);
>>   	return wr_mas.content;
>>   }
>>   EXPORT_SYMBOL_GPL(mas_store);
>> -- 
>> 2.45.2
>>
diff mbox series

Patch

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 8b17768db5f2..92f133ea5f00 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -5528,6 +5528,20 @@  static inline void mte_destroy_walk(struct maple_enode *enode,
 		mt_destroy_walk(enode, mt, true);
 	}
 }
+
+static inline void mas_wr_store_prealloc(struct ma_wr_state *wr_mas, void *entry)
+{
+	struct ma_state *mas = wr_mas->mas;
+	int request;
+
+	mas_wr_prealloc_setup(wr_mas);
+	mas_wr_store_type(wr_mas);
+	request = mas_prealloc_calc(mas, entry);
+	if (!request)
+		return;
+
+	mas_node_count(mas, request);
+}
 /* Interface */
 
 /**
@@ -5536,8 +5550,6 @@  static inline void mte_destroy_walk(struct maple_enode *enode,
  * @entry: The entry to store.
  *
  * The @mas->index and @mas->last is used to set the range for the @entry.
- * Note: The @mas should have pre-allocated entries to ensure there is memory to
- * store the entry.  Please see mas_expected_entries()/mas_destroy() for more details.
  *
  * Return: the first entry between mas->index and mas->last or %NULL.
  */
@@ -5563,9 +5575,21 @@  void *mas_store(struct ma_state *mas, void *entry)
 	 * want to examine what happens if a single store operation was to
 	 * overwrite multiple entries within a self-balancing B-Tree.
 	 */
-	mas_wr_prealloc_setup(&wr_mas);
-	mas_wr_store_type(&wr_mas);
+	if (mas->mas_flags & MA_STATE_PREALLOC) {
+		mas_wr_prealloc_setup(&wr_mas);
+		mas_wr_store_type(&wr_mas);
+		mas_wr_store_entry(&wr_mas);
+		MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
+		return wr_mas.content;
+	}
+
+	mas_wr_store_prealloc(&wr_mas, entry);
+	WARN_ON_ONCE(mas->store_type == wr_invalid);
+	if (mas_is_err(mas))
+		return NULL;
+
 	mas_wr_store_entry(&wr_mas);
+	mas_destroy(mas);
 	return wr_mas.content;
 }
 EXPORT_SYMBOL_GPL(mas_store);