The patch titled
Subject: maple_tree: refactor mas_wr_store_type()
has been added to the -mm mm-unstable branch. Its filename is
maple_tree-refactor-mas_wr_store_type.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-refactor-mas_wr_store_type.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: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Subject: maple_tree: refactor mas_wr_store_type()
Date: Fri, 11 Oct 2024 17:44:51 -0400
In mas_wr_store_type(), we check if new_end < mt_slots[wr_mas->type]. If
this check fails, we know that ,after this, new_end is >= mt_min_slots.
Checking this again when we detect a wr_node_store later in the function
is reduntant. Because this check is part of an OR statement, the
statement will always evaluate to true, therefore we can just get rid of
it.
We also refactor mas_wr_store_type() to return the store type rather than
set it directly as it greatly cleans up the function.
Link: https://lkml.kernel.org/r/20241011214451.7286-2-sidhartha.kumar@xxxxxxxxxx
Signed-off-by: Sidhartha <sidhartha.kumar@xxxxxxxxxx>
Suggested-by: Liam Howlett <liam.howlett@xxxxxxxxxx>
Suggested-by: Wei Yang <richard.weiyang@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/maple_tree.c | 72 +++++++++++++++------------------------------
1 file changed, 25 insertions(+), 47 deletions(-)
--- a/lib/maple_tree.c~maple_tree-refactor-mas_wr_store_type
+++ a/lib/maple_tree.c
@@ -4191,24 +4191,22 @@ static inline int mas_prealloc_calc(stru
}
/*
- * mas_wr_store_type() - Set the store type for a given
+ * mas_wr_store_type() - Determine the store type for a given
* store operation.
* @wr_mas: The maple write state
+ *
+ * Return: the type of store needed for the operation
*/
-static inline void mas_wr_store_type(struct ma_wr_state *wr_mas)
+static inline enum store_type mas_wr_store_type(struct ma_wr_state *wr_mas)
{
struct ma_state *mas = wr_mas->mas;
unsigned char new_end;
- if (unlikely(mas_is_none(mas) || mas_is_ptr(mas))) {
- mas->store_type = wr_store_root;
- return;
- }
+ if (unlikely(mas_is_none(mas) || mas_is_ptr(mas)))
+ return wr_store_root;
- if (unlikely(!mas_wr_walk(wr_mas))) {
- mas->store_type = wr_spanning_store;
- return;
- }
+ if (unlikely(!mas_wr_walk(wr_mas)))
+ return wr_spanning_store;
/* At this point, we are at the leaf node that needs to be altered. */
mas_wr_end_piv(wr_mas);
@@ -4216,50 +4214,30 @@ static inline void mas_wr_store_type(str
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;
- }
+ if ((wr_mas->r_min == mas->index) && (wr_mas->r_max == mas->last))
+ return wr_exact_fit;
- if (unlikely(!mas->index && mas->last == ULONG_MAX)) {
- mas->store_type = wr_new_root;
- return;
- }
+ if (unlikely(!mas->index && mas->last == ULONG_MAX))
+ return wr_new_root;
/* Potential spanning rebalance collapsing a node */
if (new_end < mt_min_slots[wr_mas->type]) {
- if (!mte_is_root(mas->node) && !(mas->mas_flags & MA_STATE_BULK)) {
- mas->store_type = wr_rebalance;
- return;
- }
- mas->store_type = wr_node_store;
- return;
+ if (!mte_is_root(mas->node) && !(mas->mas_flags & MA_STATE_BULK))
+ return wr_rebalance;
+ return wr_node_store;
}
- if (new_end >= mt_slots[wr_mas->type]) {
- mas->store_type = wr_split_store;
- return;
- }
+ if (new_end >= mt_slots[wr_mas->type])
+ return wr_split_store;
- if (!mt_in_rcu(mas->tree) && (mas->offset == mas->end)) {
- mas->store_type = wr_append;
- return;
- }
+ if (!mt_in_rcu(mas->tree) && (mas->offset == mas->end))
+ return wr_append;
if ((new_end == mas->end) && (!mt_in_rcu(mas->tree) ||
- (wr_mas->offset_end - mas->offset == 1))) {
- mas->store_type = wr_slot_store;
- return;
- }
-
- if (mte_is_root(mas->node) || (new_end >= mt_min_slots[wr_mas->type]) ||
- (mas->mas_flags & MA_STATE_BULK)) {
- mas->store_type = wr_node_store;
- return;
- }
+ (wr_mas->offset_end - mas->offset == 1)))
+ return wr_slot_store;
- mas->store_type = wr_invalid;
- MAS_WARN_ON(mas, 1);
+ return wr_node_store;
}
/**
@@ -4274,7 +4252,7 @@ static inline void mas_wr_preallocate(st
int request;
mas_wr_prealloc_setup(wr_mas);
- mas_wr_store_type(wr_mas);
+ mas->store_type = mas_wr_store_type(wr_mas);
request = mas_prealloc_calc(mas, entry);
if (!request)
return;
@@ -5446,7 +5424,7 @@ void *mas_store(struct ma_state *mas, vo
* overwrite multiple entries within a self-balancing B-Tree.
*/
mas_wr_prealloc_setup(&wr_mas);
- mas_wr_store_type(&wr_mas);
+ mas->store_type = mas_wr_store_type(&wr_mas);
if (mas->mas_flags & MA_STATE_PREALLOC) {
mas_wr_store_entry(&wr_mas);
MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
@@ -5549,7 +5527,7 @@ int mas_preallocate(struct ma_state *mas
int request;
mas_wr_prealloc_setup(&wr_mas);
- mas_wr_store_type(&wr_mas);
+ mas->store_type = mas_wr_store_type(&wr_mas);
request = mas_prealloc_calc(mas, entry);
if (!request)
return ret;
_
Patches currently in -mm which might be from sidhartha.kumar@xxxxxxxxxx are
maple_tree-check-for-ma_state_bulk-on-setting-wr_rebalance.patch
maple_tree-refactor-mas_wr_store_type.patch
