The patch titled
Subject: maple_tree: clean up mas_wr_append()
has been added to the -mm mm-unstable branch. Its filename is
maple_tree-clean-up-mas_wr_append.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-clean-up-mas_wr_append.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Subject: maple_tree: clean up mas_wr_append()
Date: Fri, 18 Aug 2023 20:43:56 -0400
Avoid setting the variables until necessary, and actually use the
variables where applicable. Introducing a variable for the slots array
avoids spanning multiple lines.
Add the missing argument to the documentation.
Use the node type when setting the metadata instead of blindly assuming
the type.
Finally, add a trace point to the function for successful store.
Link: https://lkml.kernel.org/r/20230819004356.1454718-3-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/maple_tree.c | 34 ++++++++++++++++++++--------------
1 file changed, 20 insertions(+), 14 deletions(-)
--- a/lib/maple_tree.c~maple_tree-clean-up-mas_wr_append
+++ a/lib/maple_tree.c
@@ -4106,6 +4106,7 @@ static inline unsigned char mas_wr_new_e
/*
* mas_wr_append: Attempt to append
* @wr_mas: the maple write state
+ * @new_end: The end of the node after the modification
*
* This is currently unsafe in rcu mode since the end of the node may be cached
* by readers while the node contents may be updated which could result in
@@ -4114,42 +4115,46 @@ static inline unsigned char mas_wr_new_e
* Return: True if appended, false otherwise
*/
static inline bool mas_wr_append(struct ma_wr_state *wr_mas,
- unsigned char new_end)
+ unsigned char new_end)
{
- unsigned char end = wr_mas->node_end;
- struct ma_state *mas = wr_mas->mas;
- unsigned char node_pivots = mt_pivots[wr_mas->type];
+ struct ma_state *mas;
+ void __rcu **slots;
+ unsigned char end;
+ mas = wr_mas->mas;
if (mt_in_rcu(mas->tree))
return false;
if (mas->offset != wr_mas->node_end)
return false;
- if (new_end < node_pivots) {
+ end = wr_mas->node_end;
+ if (mas->offset != end)
+ return false;
+
+ if (new_end < mt_pivots[wr_mas->type]) {
wr_mas->pivots[new_end] = wr_mas->pivots[end];
- ma_set_meta(wr_mas->node, maple_leaf_64, 0, new_end);
+ ma_set_meta(wr_mas->node, wr_mas->type, 0, new_end);
}
- if (new_end == wr_mas->node_end + 1) {
+ slots = wr_mas->slots;
+ if (new_end == end + 1) {
if (mas->last == wr_mas->r_max) {
/* Append to end of range */
- rcu_assign_pointer(wr_mas->slots[new_end],
- wr_mas->entry);
+ rcu_assign_pointer(slots[new_end], wr_mas->entry);
wr_mas->pivots[end] = mas->index - 1;
mas->offset = new_end;
} else {
/* Append to start of range */
- rcu_assign_pointer(wr_mas->slots[new_end],
- wr_mas->content);
+ rcu_assign_pointer(slots[new_end], wr_mas->content);
wr_mas->pivots[end] = mas->last;
- rcu_assign_pointer(wr_mas->slots[end], wr_mas->entry);
+ rcu_assign_pointer(slots[end], wr_mas->entry);
}
} else {
/* Append to the range without touching any boundaries. */
- rcu_assign_pointer(wr_mas->slots[new_end], wr_mas->content);
+ rcu_assign_pointer(slots[new_end], wr_mas->content);
wr_mas->pivots[end + 1] = mas->last;
- rcu_assign_pointer(wr_mas->slots[end + 1], wr_mas->entry);
+ rcu_assign_pointer(slots[end + 1], wr_mas->entry);
wr_mas->pivots[end] = mas->index - 1;
mas->offset = end + 1;
}
@@ -4157,6 +4162,7 @@ static inline bool mas_wr_append(struct
if (!wr_mas->content || !wr_mas->entry)
mas_update_gap(mas);
+ trace_ma_write(__func__, mas, new_end, wr_mas->entry);
return true;
}
_
Patches currently in -mm which might be from Liam.Howlett@xxxxxxxxxx are
maple_tree-disable-mas_wr_append-when-other-readers-are-possible.patch
maple_tree-add-hex-output-to-maple_arange64-dump.patch
maple_tree-reorder-replacement-of-nodes-to-avoid-live-lock.patch
maple_tree-introduce-mas_put_in_tree.patch
maple_tree-introduce-mas_tree_parent-definition.patch
maple_tree-change-mas_adopt_children-parent-usage.patch
maple_tree-replace-data-before-marking-dead-in-split-and-spanning-store.patch
maple_tree-clean-up-mas_wr_append.patch
