From: Lukáš Ondráček <lukas.ondracek@nic.cz>
Date: Mon, 22 Jun 2026 15:45:00 +0000 (+0200)
Subject: lib/generic/array: round sizes to those used by jemalloc
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=refs%2Fheads%2Farray-growth;p=thirdparty%2Fknot-resolver.git

lib/generic/array: round sizes to those used by jemalloc
---

diff --git a/lib/generic/array.h b/lib/generic/array.h
index 39caed2a4..dd684ae5a 100644
--- a/lib/generic/array.h
+++ b/lib/generic/array.h
@@ -57,8 +57,9 @@
 static inline size_t array_next_count(size_t elm_size, size_t want, size_t have)
 {
 	// round size to power of two
-	const size_t want_b = MAX(want, 4) * elm_size;
-	const size_t next_b =  1 << (8 * sizeof(unsigned int) - __builtin_clz(want_b - 1));
+	const size_t want_b = MAX(want * elm_size, 32);
+	const size_t msb_index = 8 * sizeof(unsigned int) - __builtin_clz(want_b - 1);
+	const size_t next_b = (((want_b - 1) >> (msb_index - 3)) + 1) << (msb_index - 3);
 	return next_b / elm_size;
 }