Users of mas_store_prealloc() enter this function with nodes already
preallocated. This means the store type must be already set. We can then
remove the call to mas_wr_store_type() and initialize the write state to
continue the partial walk that was done when determining the store type.

Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
---
 lib/maple_tree.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 8c1a1a483395..73ce63d9c3a0 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3979,9 +3979,6 @@ static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas)
 		wr_mas->end_piv = wr_mas->pivots[wr_mas->offset_end];
 	else
 		wr_mas->end_piv = wr_mas->mas->max;
-
-	if (!wr_mas->entry)
-		mas_wr_extend_null(wr_mas);
 }
 
 static inline unsigned char mas_wr_new_end(struct ma_wr_state *wr_mas)
@@ -5532,8 +5529,19 @@ void mas_store_prealloc(struct ma_state *mas, void *entry)
 {
 	MA_WR_STATE(wr_mas, mas, entry);
 
-	mas_wr_prealloc_setup(&wr_mas);
-	mas_wr_store_type(&wr_mas);
+	if (mas->store_type == wr_store_root) {
+		mas_wr_prealloc_setup(&wr_mas);
+		goto store;
+	}
+
+	mas_wr_walk_descend(&wr_mas);
+	if (mas->store_type != wr_spanning_store) {
+		/* set wr_mas->content to current slot */
+		wr_mas.content = mas_slot_locked(mas, wr_mas.slots, mas->offset);
+		mas_wr_end_piv(&wr_mas);
+	}
+
+store:
 	trace_ma_write(__func__, mas, 0, entry);
 	mas_wr_store_entry(&wr_mas);
 	MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
-- 
2.46.0

On Wed, Aug 14, 2024 at 12:19:43PM -0400, Sidhartha Kumar wrote:
>Users of mas_store_prealloc() enter this function with nodes already
>preallocated. This means the store type must be already set. We can then
>remove the call to mas_wr_store_type() and initialize the write state to
>continue the partial walk that was done when determining the store type.
>

May I ask what is the partial walk here means?

It is the mas_wr_walk() in mas_wr_store_type() which is stopped because of it
is spanning write?

I may lost some background, so the assumption here is mas_wr_store_type() has
already been invoked and the store type has been decided, right?

>Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
>Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
>---
> lib/maple_tree.c | 18 +++++++++++++-----
> 1 file changed, 13 insertions(+), 5 deletions(-)
>
>diff --git a/lib/maple_tree.c b/lib/maple_tree.c
>index 8c1a1a483395..73ce63d9c3a0 100644
>--- a/lib/maple_tree.c
>+++ b/lib/maple_tree.c
>@@ -3979,9 +3979,6 @@ static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas)
> 		wr_mas->end_piv = wr_mas->pivots[wr_mas->offset_end];
> 	else
> 		wr_mas->end_piv = wr_mas->mas->max;
>-
>-	if (!wr_mas->entry)
>-		mas_wr_extend_null(wr_mas);
> }
> 
> static inline unsigned char mas_wr_new_end(struct ma_wr_state *wr_mas)
>@@ -5532,8 +5529,19 @@ void mas_store_prealloc(struct ma_state *mas, void *entry)
> {
> 	MA_WR_STATE(wr_mas, mas, entry);
> 
>-	mas_wr_prealloc_setup(&wr_mas);
>-	mas_wr_store_type(&wr_mas);
>+	if (mas->store_type == wr_store_root) {
>+		mas_wr_prealloc_setup(&wr_mas);
>+		goto store;
>+	}
>+
>+	mas_wr_walk_descend(&wr_mas);

This one does not descend the tree, just locate the offset in a node and
adjust min/max. So not look like to continue the partial walk to me.

>+	if (mas->store_type != wr_spanning_store) {
>+		/* set wr_mas->content to current slot */
>+		wr_mas.content = mas_slot_locked(mas, wr_mas.slots, mas->offset);
>+		mas_wr_end_piv(&wr_mas);

If not a spanning write, the previous walk should reach a leaf node, right?

I am not sure why we don't need to check extend null here. Because we have
already done it?

>+	}
>+
>+store:
> 	trace_ma_write(__func__, mas, 0, entry);
> 	mas_wr_store_entry(&wr_mas);
> 	MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
>-- 
>2.46.0
>

-- 
Wei Yang
Help you, Help me

On 10/23/24 9:20 PM, Wei Yang wrote:
> On Wed, Aug 14, 2024 at 12:19:43PM -0400, Sidhartha Kumar wrote:
>> Users of mas_store_prealloc() enter this function with nodes already
>> preallocated. This means the store type must be already set. We can then
>> remove the call to mas_wr_store_type() and initialize the write state to
>> continue the partial walk that was done when determining the store type.
>>
> May I ask what is the partial walk here means?
>
> It is the mas_wr_walk() in mas_wr_store_type() which is stopped because of it
> is spanning write?

Yes, this is what I meant by the partial walk that's already been 
started. It's the walk done by mas_wr_store_type().

> I may lost some background, so the assumption here is mas_wr_store_type() has
> already been invoked and the store type has been decided, right?

Ya users of mas_store_prealloc() should have already called 
mas_preallocate() which does:

     mas->store_type = mas_wr_store_type(&wr_mas);
     request = mas_prealloc_calc(&wr_mas, entry);

to set the store type and allocate the nodes.


>> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
>> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
>> ---
>> lib/maple_tree.c | 18 +++++++++++++-----
>> 1 file changed, 13 insertions(+), 5 deletions(-)
>>
>> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
>> index 8c1a1a483395..73ce63d9c3a0 100644
>> --- a/lib/maple_tree.c
>> +++ b/lib/maple_tree.c
>> @@ -3979,9 +3979,6 @@ static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas)
>> 		wr_mas->end_piv = wr_mas->pivots[wr_mas->offset_end];
>> 	else
>> 		wr_mas->end_piv = wr_mas->mas->max;
>> -
>> -	if (!wr_mas->entry)
>> -		mas_wr_extend_null(wr_mas);
>> }
>>
>> static inline unsigned char mas_wr_new_end(struct ma_wr_state *wr_mas)
>> @@ -5532,8 +5529,19 @@ void mas_store_prealloc(struct ma_state *mas, void *entry)
>> {
>> 	MA_WR_STATE(wr_mas, mas, entry);
>>
>> -	mas_wr_prealloc_setup(&wr_mas);
>> -	mas_wr_store_type(&wr_mas);
>> +	if (mas->store_type == wr_store_root) {
>> +		mas_wr_prealloc_setup(&wr_mas);
>> +		goto store;
>> +	}
>> +
>> +	mas_wr_walk_descend(&wr_mas);
> This one does not descend the tree, just locate the offset in a node and
> adjust min/max. So not look like to continue the partial walk to me.
>
>> +	if (mas->store_type != wr_spanning_store) {
>> +		/* set wr_mas->content to current slot */
>> +		wr_mas.content = mas_slot_locked(mas, wr_mas.slots, mas->offset);
>> +		mas_wr_end_piv(&wr_mas);
> If not a spanning write, the previous walk should reach a leaf node, right?

Ya that's true.

> I am not sure why we don't need to check extend null here. Because we have
> already done it?


Ya we extend null in mas_wr_store_type() which has already been called 
at this point.


     /* At this point, we are at the leaf node that needs to be altered. */
     mas_wr_end_piv(wr_mas);
     if (!wr_mas->entry)
         mas_wr_extend_null(wr_mas);

Thanks,

Sid

>> +	}
>> +
>> +store:
>> 	trace_ma_write(__func__, mas, 0, entry);
>> 	mas_wr_store_entry(&wr_mas);
>> 	MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
>> -- 
>> 2.46.0
>>

On Fri, Oct 25, 2024 at 03:54:04PM -0400, Sid Kumar wrote:
>
>On 10/23/24 9:20 PM, Wei Yang wrote:
>> On Wed, Aug 14, 2024 at 12:19:43PM -0400, Sidhartha Kumar wrote:
>> > Users of mas_store_prealloc() enter this function with nodes already
>> > preallocated. This means the store type must be already set. We can then
>> > remove the call to mas_wr_store_type() and initialize the write state to
>> > continue the partial walk that was done when determining the store type.
>> > 
>> May I ask what is the partial walk here means?
>> 
>> It is the mas_wr_walk() in mas_wr_store_type() which is stopped because of it
>> is spanning write?
>
>Yes, this is what I meant by the partial walk that's already been started.
>It's the walk done by mas_wr_store_type().
>
>> I may lost some background, so the assumption here is mas_wr_store_type() has
>> already been invoked and the store type has been decided, right?
>
>Ya users of mas_store_prealloc() should have already called mas_preallocate()
>which does:
>
>    mas->store_type = mas_wr_store_type(&wr_mas);
>    request = mas_prealloc_calc(&wr_mas, entry);
>
>to set the store type and allocate the nodes.
>
>
>> > Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
>> > Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
>> > ---
>> > lib/maple_tree.c | 18 +++++++++++++-----
>> > 1 file changed, 13 insertions(+), 5 deletions(-)
>> > 
>> > diff --git a/lib/maple_tree.c b/lib/maple_tree.c
>> > index 8c1a1a483395..73ce63d9c3a0 100644
>> > --- a/lib/maple_tree.c
>> > +++ b/lib/maple_tree.c
>> > @@ -3979,9 +3979,6 @@ static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas)
>> > 		wr_mas->end_piv = wr_mas->pivots[wr_mas->offset_end];
>> > 	else
>> > 		wr_mas->end_piv = wr_mas->mas->max;
>> > -
>> > -	if (!wr_mas->entry)
>> > -		mas_wr_extend_null(wr_mas);
>> > }
>> > 
>> > static inline unsigned char mas_wr_new_end(struct ma_wr_state *wr_mas)
>> > @@ -5532,8 +5529,19 @@ void mas_store_prealloc(struct ma_state *mas, void *entry)
>> > {
>> > 	MA_WR_STATE(wr_mas, mas, entry);
>> > 
>> > -	mas_wr_prealloc_setup(&wr_mas);
>> > -	mas_wr_store_type(&wr_mas);
>> > +	if (mas->store_type == wr_store_root) {
>> > +		mas_wr_prealloc_setup(&wr_mas);
>> > +		goto store;
>> > +	}
>> > +
>> > +	mas_wr_walk_descend(&wr_mas);
>> This one does not descend the tree, just locate the offset in a node and
>> adjust min/max. So not look like to continue the partial walk to me.
>> 
>> > +	if (mas->store_type != wr_spanning_store) {
>> > +		/* set wr_mas->content to current slot */
>> > +		wr_mas.content = mas_slot_locked(mas, wr_mas.slots, mas->offset);
>> > +		mas_wr_end_piv(&wr_mas);
>> If not a spanning write, the previous walk should reach a leaf node, right?
>
>Ya that's true.
>
>> I am not sure why we don't need to check extend null here. Because we have
>> already done it?
>
>
>Ya we extend null in mas_wr_store_type() which has already been called at
>this point.
>
>
>    /* At this point, we are at the leaf node that needs to be altered. */
>    mas_wr_end_piv(wr_mas);
>    if (!wr_mas->entry)
>        mas_wr_extend_null(wr_mas);
>
>Thanks,

Hmm... if we have already done this, why we need to do mas_wr_end_piv() again?

>
>Sid
>
>> > +	}
>> > +
>> > +store:
>> > 	trace_ma_write(__func__, mas, 0, entry);
>> > 	mas_wr_store_entry(&wr_mas);
>> > 	MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
>> > -- 
>> > 2.46.0
>> > 

-- 
Wei Yang
Help you, Help me

On 10/25/24 7:58 PM, Wei Yang wrote:
> On Fri, Oct 25, 2024 at 03:54:04PM -0400, Sid Kumar wrote:
>> On 10/23/24 9:20 PM, Wei Yang wrote:
>>> On Wed, Aug 14, 2024 at 12:19:43PM -0400, Sidhartha Kumar wrote:
>>>> Users of mas_store_prealloc() enter this function with nodes already
>>>> preallocated. This means the store type must be already set. We can then
>>>> remove the call to mas_wr_store_type() and initialize the write state to
>>>> continue the partial walk that was done when determining the store type.
>>>>
>>> May I ask what is the partial walk here means?
>>>
>>> It is the mas_wr_walk() in mas_wr_store_type() which is stopped because of it
>>> is spanning write?
>> Yes, this is what I meant by the partial walk that's already been started.
>> It's the walk done by mas_wr_store_type().
>>
>>> I may lost some background, so the assumption here is mas_wr_store_type() has
>>> already been invoked and the store type has been decided, right?
>> Ya users of mas_store_prealloc() should have already called mas_preallocate()
>> which does:
>>
>>      mas->store_type = mas_wr_store_type(&wr_mas);
>>      request = mas_prealloc_calc(&wr_mas, entry);
>>
>> to set the store type and allocate the nodes.
>>
>>
>>>> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
>>>> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
>>>> ---
>>>> lib/maple_tree.c | 18 +++++++++++++-----
>>>> 1 file changed, 13 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
>>>> index 8c1a1a483395..73ce63d9c3a0 100644
>>>> --- a/lib/maple_tree.c
>>>> +++ b/lib/maple_tree.c
>>>> @@ -3979,9 +3979,6 @@ static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas)
>>>> 		wr_mas->end_piv = wr_mas->pivots[wr_mas->offset_end];
>>>> 	else
>>>> 		wr_mas->end_piv = wr_mas->mas->max;
>>>> -
>>>> -	if (!wr_mas->entry)
>>>> -		mas_wr_extend_null(wr_mas);
>>>> }
>>>>
>>>> static inline unsigned char mas_wr_new_end(struct ma_wr_state *wr_mas)
>>>> @@ -5532,8 +5529,19 @@ void mas_store_prealloc(struct ma_state *mas, void *entry)
>>>> {
>>>> 	MA_WR_STATE(wr_mas, mas, entry);
>>>>
>>>> -	mas_wr_prealloc_setup(&wr_mas);
>>>> -	mas_wr_store_type(&wr_mas);
>>>> +	if (mas->store_type == wr_store_root) {
>>>> +		mas_wr_prealloc_setup(&wr_mas);
>>>> +		goto store;
>>>> +	}
>>>> +
>>>> +	mas_wr_walk_descend(&wr_mas);
>>> This one does not descend the tree, just locate the offset in a node and
>>> adjust min/max. So not look like to continue the partial walk to me.
>>>
>>>> +	if (mas->store_type != wr_spanning_store) {
>>>> +		/* set wr_mas->content to current slot */
>>>> +		wr_mas.content = mas_slot_locked(mas, wr_mas.slots, mas->offset);
>>>> +		mas_wr_end_piv(&wr_mas);
>>> If not a spanning write, the previous walk should reach a leaf node, right?
>> Ya that's true.
>>
>>> I am not sure why we don't need to check extend null here. Because we have
>>> already done it?
>>
>> Ya we extend null in mas_wr_store_type() which has already been called at
>> this point.
>>
>>
>>      /* At this point, we are at the leaf node that needs to be altered. */
>>      mas_wr_end_piv(wr_mas);
>>      if (!wr_mas->entry)
>>          mas_wr_extend_null(wr_mas);
>>
>> Thanks,
> Hmm... if we have already done this, why we need to do mas_wr_end_piv() again?

The maple write state here is local to this function:

void mas_store_prealloc(struct ma_state *mas, void *entry)
{
     MA_WR_STATE(wr_mas, mas, entry);

so we don't retain the wr_end information from the previous call to 
mas_preallocate() and have to repeat it here. The write state is not 
currently exposed so have to call mas_wr_end_piv() again.

Thanks,

Sid


>
>> Sid
>>
>>>> +	}
>>>> +
>>>> +store:
>>>> 	trace_ma_write(__func__, mas, 0, entry);
>>>> 	mas_wr_store_entry(&wr_mas);
>>>> 	MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
>>>> -- 
>>>> 2.46.0
>>>>

On Tue, Oct 29, 2024 at 11:46:58AM -0400, Sid Kumar wrote:
>
>On 10/25/24 7:58 PM, Wei Yang wrote:
>> On Fri, Oct 25, 2024 at 03:54:04PM -0400, Sid Kumar wrote:
>> > On 10/23/24 9:20 PM, Wei Yang wrote:
>> > > On Wed, Aug 14, 2024 at 12:19:43PM -0400, Sidhartha Kumar wrote:
>> > > > Users of mas_store_prealloc() enter this function with nodes already
>> > > > preallocated. This means the store type must be already set. We can then
>> > > > remove the call to mas_wr_store_type() and initialize the write state to
>> > > > continue the partial walk that was done when determining the store type.
>> > > > 
>> > > May I ask what is the partial walk here means?
>> > > 
>> > > It is the mas_wr_walk() in mas_wr_store_type() which is stopped because of it
>> > > is spanning write?
>> > Yes, this is what I meant by the partial walk that's already been started.
>> > It's the walk done by mas_wr_store_type().
>> > 
>> > > I may lost some background, so the assumption here is mas_wr_store_type() has
>> > > already been invoked and the store type has been decided, right?
>> > Ya users of mas_store_prealloc() should have already called mas_preallocate()
>> > which does:
>> > 
>> >      mas->store_type = mas_wr_store_type(&wr_mas);
>> >      request = mas_prealloc_calc(&wr_mas, entry);
>> > 
>> > to set the store type and allocate the nodes.
>> > 
>> > 
>> > > > Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
>> > > > Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
>> > > > ---
>> > > > lib/maple_tree.c | 18 +++++++++++++-----
>> > > > 1 file changed, 13 insertions(+), 5 deletions(-)
>> > > > 
>> > > > diff --git a/lib/maple_tree.c b/lib/maple_tree.c
>> > > > index 8c1a1a483395..73ce63d9c3a0 100644
>> > > > --- a/lib/maple_tree.c
>> > > > +++ b/lib/maple_tree.c
>> > > > @@ -3979,9 +3979,6 @@ static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas)
>> > > > 		wr_mas->end_piv = wr_mas->pivots[wr_mas->offset_end];
>> > > > 	else
>> > > > 		wr_mas->end_piv = wr_mas->mas->max;
>> > > > -
>> > > > -	if (!wr_mas->entry)
>> > > > -		mas_wr_extend_null(wr_mas);
>> > > > }
>> > > > 
>> > > > static inline unsigned char mas_wr_new_end(struct ma_wr_state *wr_mas)
>> > > > @@ -5532,8 +5529,19 @@ void mas_store_prealloc(struct ma_state *mas, void *entry)
>> > > > {
>> > > > 	MA_WR_STATE(wr_mas, mas, entry);
>> > > > 
>> > > > -	mas_wr_prealloc_setup(&wr_mas);
>> > > > -	mas_wr_store_type(&wr_mas);
>> > > > +	if (mas->store_type == wr_store_root) {
>> > > > +		mas_wr_prealloc_setup(&wr_mas);
>> > > > +		goto store;
>> > > > +	}
>> > > > +
>> > > > +	mas_wr_walk_descend(&wr_mas);
>> > > This one does not descend the tree, just locate the offset in a node and
>> > > adjust min/max. So not look like to continue the partial walk to me.
>> > > 
>> > > > +	if (mas->store_type != wr_spanning_store) {
>> > > > +		/* set wr_mas->content to current slot */
>> > > > +		wr_mas.content = mas_slot_locked(mas, wr_mas.slots, mas->offset);
>> > > > +		mas_wr_end_piv(&wr_mas);
>> > > If not a spanning write, the previous walk should reach a leaf node, right?
>> > Ya that's true.
>> > 
>> > > I am not sure why we don't need to check extend null here. Because we have
>> > > already done it?
>> > 
>> > Ya we extend null in mas_wr_store_type() which has already been called at
>> > this point.
>> > 
>> > 
>> >      /* At this point, we are at the leaf node that needs to be altered. */
>> >      mas_wr_end_piv(wr_mas);
>> >      if (!wr_mas->entry)
>> >          mas_wr_extend_null(wr_mas);
>> > 
>> > Thanks,
>> Hmm... if we have already done this, why we need to do mas_wr_end_piv() again?
>
>The maple write state here is local to this function:
>
>void mas_store_prealloc(struct ma_state *mas, void *entry)
>{
>    MA_WR_STATE(wr_mas, mas, entry);
>
>so we don't retain the wr_end information from the previous call to
>mas_preallocate() and have to repeat it here. The write state is not
>currently exposed so have to call mas_wr_end_piv() again.
>

Thanks, I missed this point.

>Thanks,
>
>Sid
>
>
>> 
>> > Sid
>> > 
>> > > > +	}
>> > > > +
>> > > > +store:
>> > > > 	trace_ma_write(__func__, mas, 0, entry);
>> > > > 	mas_wr_store_entry(&wr_mas);
>> > > > 	MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
>> > > > -- 
>> > > > 2.46.0
>> > > > 

-- 
Wei Yang
Help you, Help me