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maple_tree: micro optimisation of mas_wr_store_type()

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Use three new local booleans instead of reading other structures.  This
has shown an increase of 0.62% on a 2048 entry tree of height 4.

Link: https://lore.kernel.org/20260821192627.4085470-11-liam@infradead.org
Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Chris Mason <clm@meta.com>
Cc: Chuck Lever <cel@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joe Perches <joe@perches.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Liam R. Howlett (Oracle)
2026-08-21 15:26:18 -04:00
committed by Andrew Morton
parent 88f87f8812
commit f0a3892cd7
1 changed files with 15 additions and 3 deletions
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18
lib/maple_tree.c
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@@ -3737,6 +3737,9 @@ 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;
bool appending;
bool one_slot;
bool in_rcu;
if (unlikely(mas_is_none(mas) || mas_is_ptr(mas)))
return wr_store_root;
@@ -3756,21 +3759,30 @@ static inline enum store_type mas_wr_store_type(struct ma_wr_state *wr_mas)
return wr_new_root;
new_end = mas_wr_new_end(wr_mas);
in_rcu = mt_in_rcu(mas->tree);
appending = mas->offset == mas->end;
one_slot = wr_mas->offset_end - mas->offset == 1;
/* Potential spanning rebalance collapsing a node */
if (new_end < mt_min_slots[wr_mas->type]) {
if (!mte_is_root(mas->node))
return wr_rebalance;
if (!in_rcu) {
if (appending)
return wr_append;
else if (mas->end == new_end && one_slot)
return wr_slot_store;
}
return wr_node_store;
}
if (new_end >= mt_slots[wr_mas->type])
return wr_split_store;
if (!mt_in_rcu(mas->tree) && (mas->offset == mas->end))
if (!in_rcu && appending)
return wr_append;
if ((new_end == mas->end) && (!mt_in_rcu(mas->tree) ||
(wr_mas->offset_end - mas->offset == 1)))
if (new_end == mas->end && (!in_rcu || one_slot))
return wr_slot_store;
return wr_node_store;