From 7e552dcd803f4ff60165271c573ab2e38d15769f Mon Sep 17 00:00:00 2001 From: Peng Zhang Date: Fri, 15 Dec 2023 15:46:32 +0800 Subject: [PATCH] maple_tree: avoid checking other gaps after getting the largest gap The last range stored in maple tree is typically quite large. By checking if it exceeds the sum of the remaining ranges in that node, it is possible to avoid checking all other gaps. Running the maple tree test suite in user mode almost always results in a near 100% hit rate for this optimization. Link: https://lkml.kernel.org/r/20231215074632.82045-1-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang Reviewed-by: Liam R. Howlett Signed-off-by: Andrew Morton --- lib/maple_tree.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/lib/maple_tree.c b/lib/maple_tree.c index c9a970ea20dd5..6f241bb387992 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -1518,6 +1518,9 @@ static unsigned long mas_leaf_max_gap(struct ma_state *mas) gap = ULONG_MAX - pivots[max_piv]; if (gap > max_gap) max_gap = gap; + + if (max_gap > pivots[max_piv] - mas->min) + return max_gap; } for (; i <= max_piv; i++) { -- 2.30.2