The patch titled
Subject: maple_tree: use store type in mas_wr_store_entry()
has been added to the -mm mm-unstable branch. Its filename is
maple_tree-use-store-type-in-mas_wr_store_entry.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-use-store-type-in-mas_wr_store_entry.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: use store type in mas_wr_store_entry()
Date: Wed, 14 Aug 2024 12:19:36 -0400
When storing an entry, we can read the store type that was set from a
previous partial walk of the tree. Now that the type of store is known,
select the correct write helper function to use to complete the store.
Also noinline mas_wr_spanning_store() to limit stack frame usage in
mas_wr_store_entry() as it allocates a maple_big_node on the stack.
Link: https://lkml.kernel.org/r/20240814161944.55347-10-sidhartha.kumar@xxxxxxxxxx
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/maple_tree.c | 90 ++++++++++++++++++++++++++-------------------
1 file changed, 52 insertions(+), 38 deletions(-)
--- a/lib/maple_tree.c~maple_tree-use-store-type-in-mas_wr_store_entry
+++ a/lib/maple_tree.c
@@ -3780,7 +3780,7 @@ done:
*
* Return: 0 on error, positive on success.
*/
-static inline int mas_wr_spanning_store(struct ma_wr_state *wr_mas)
+static noinline int mas_wr_spanning_store(struct ma_wr_state *wr_mas)
{
struct maple_subtree_state mast;
struct maple_big_node b_node;
@@ -4206,43 +4206,62 @@ slow_path:
static inline void mas_wr_store_entry(struct ma_wr_state *wr_mas)
{
struct ma_state *mas = wr_mas->mas;
+ unsigned char new_end = mas_wr_new_end(wr_mas);
- wr_mas->content = mas_start(mas);
- if (mas_is_none(mas) || mas_is_ptr(mas)) {
- mas_store_root(mas, wr_mas->entry);
+ switch (mas->store_type) {
+ case wr_invalid:
+ MT_BUG_ON(mas->tree, 1);
return;
- }
-
- if (unlikely(!mas_wr_walk(wr_mas))) {
+ case wr_new_root:
+ mas_new_root(mas, wr_mas->entry);
+ break;
+ case wr_store_root:
+ mas_store_root(mas, wr_mas->entry);
+ break;
+ case wr_exact_fit:
+ rcu_assign_pointer(wr_mas->slots[mas->offset], wr_mas->entry);
+ if (!!wr_mas->entry ^ !!wr_mas->content)
+ mas_update_gap(mas);
+ break;
+ case wr_append:
+ mas_wr_append(wr_mas, new_end);
+ break;
+ case wr_slot_store:
+ mas_wr_slot_store(wr_mas);
+ break;
+ case wr_node_store:
+ mas_wr_node_store(wr_mas, new_end);
+ break;
+ case wr_spanning_store:
mas_wr_spanning_store(wr_mas);
- return;
+ break;
+ case wr_split_store:
+ case wr_rebalance:
+ mas_wr_bnode(wr_mas);
+ break;
}
- /* At this point, we are at the leaf node that needs to be altered. */
- mas_wr_end_piv(wr_mas);
- /* New root for a single pointer */
- if (unlikely(!mas->index && mas->last == ULONG_MAX))
- mas_new_root(mas, wr_mas->entry);
- else
- mas_wr_modify(wr_mas);
+ return;
}
-static void mas_wr_store_setup(struct ma_wr_state *wr_mas)
+static inline void mas_wr_prealloc_setup(struct ma_wr_state *wr_mas)
{
- if (!mas_is_active(wr_mas->mas)) {
- if (mas_is_start(wr_mas->mas))
- return;
+ struct ma_state *mas = wr_mas->mas;
- if (unlikely(mas_is_paused(wr_mas->mas)))
+ if (!mas_is_active(mas)) {
+ if (mas_is_start(mas))
+ goto set_content;
+
+ if (unlikely(mas_is_paused(mas)))
goto reset;
- if (unlikely(mas_is_none(wr_mas->mas)))
+ if (unlikely(mas_is_none(mas)))
goto reset;
- if (unlikely(mas_is_overflow(wr_mas->mas)))
+ if (unlikely(mas_is_overflow(mas)))
goto reset;
- if (unlikely(mas_is_underflow(wr_mas->mas)))
+ if (unlikely(mas_is_underflow(mas)))
goto reset;
}
@@ -4251,27 +4270,20 @@ static void mas_wr_store_setup(struct ma
* writes within this node. This is to stop partial walks in
* mas_prealloc() from being reset.
*/
- if (wr_mas->mas->last > wr_mas->mas->max)
+ if (mas->last > mas->max)
goto reset;
if (wr_mas->entry)
- return;
+ goto set_content;
- if (mte_is_leaf(wr_mas->mas->node) &&
- wr_mas->mas->last == wr_mas->mas->max)
+ if (mte_is_leaf(mas->node) && mas->last == mas->max)
goto reset;
- return;
+ goto set_content;
reset:
- mas_reset(wr_mas->mas);
-}
-
-static inline void mas_wr_prealloc_setup(struct ma_wr_state *wr_mas)
-{
- struct ma_state *mas = wr_mas->mas;
-
- mas_wr_store_setup(wr_mas);
+ mas_reset(mas);
+set_content:
wr_mas->content = mas_start(mas);
}
@@ -5582,7 +5594,8 @@ void *mas_store(struct ma_state *mas, vo
* want to examine what happens if a single store operation was to
* overwrite multiple entries within a self-balancing B-Tree.
*/
- mas_wr_store_setup(&wr_mas);
+ mas_wr_prealloc_setup(&wr_mas);
+ mas_wr_store_type(&wr_mas);
mas_wr_store_entry(&wr_mas);
return wr_mas.content;
}
@@ -5634,7 +5647,8 @@ void mas_store_prealloc(struct ma_state
{
MA_WR_STATE(wr_mas, mas, entry);
- mas_wr_store_setup(&wr_mas);
+ mas_wr_prealloc_setup(&wr_mas);
+ mas_wr_store_type(&wr_mas);
trace_ma_write(__func__, mas, 0, entry);
mas_wr_store_entry(&wr_mas);
MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
_
Patches currently in -mm which might be from sidhartha.kumar@xxxxxxxxxx are
maple_tree-reset-mas-index-and-mas-last-on-write-retries.patch
maple_tree-add-test-to-replicate-low-memory-race-conditions.patch
maple_tree-introduce-store_type-enum.patch
maple_tree-introduce-mas_wr_prealloc_setup.patch
maple_tree-move-up-mas_wr_store_setup-and-mas_wr_prealloc_setup.patch
maple_tree-introduce-mas_wr_store_type.patch
maple_tree-remove-mas_destroy-from-mas_nomem.patch
maple_tree-preallocate-nodes-in-mas_erase.patch
maple_tree-use-mas_store_gfp-in-mtree_store_range.patch
maple_tree-print-store-type-in-mas_dump.patch
maple_tree-use-store-type-in-mas_wr_store_entry.patch
maple_tree-convert-mas_insert-to-preallocate-nodes.patch
maple_tree-simplify-mas_commit_b_node.patch
maple_tree-remove-mas_wr_modify.patch
maple_tree-have-mas_store-allocate-nodes-if-needed.patch
maple_tree-remove-node-allocations-from-various-write-helper-functions.patch
maple_tree-remove-repeated-sanity-checks-from-write-helper-functions.patch
maple_tree-remove-unneeded-mas_wr_walk-in-mas_store_prealloc.patch
maple_tree-make-write-helper-functions-void.patch
