From d7f6e13c424b09b66eb8dda07218a955086fd5b6 Mon Sep 17 00:00:00 2001
From: lexprfuncall <5360361+lexprfuncall@users.noreply.github.com>
Date: Thu, 7 Aug 2025 12:33:53 -0700
Subject: [PATCH] Provide hugepage advice only when the THP enabled setting is
 madvise

When THP is enabled system-wide, there is no need to provide hugepage
advice to enable THP for a region of memory.  On the other hand, when
the THP defragmentation mode is defer+madvise, hugepage advice can
result in unwanted application stalls to compact and defragment memory
if THP is not immediately available for allocation.
---
 src/hpa.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/hpa.c b/src/hpa.c
index e297e41120..e18f842484 100644
--- a/src/hpa.c
+++ b/src/hpa.c
@@ -716,7 +716,8 @@ hpa_shard_maybe_do_deferred_work(
 	 * Try to hugify at least once, even if we out of operations to make at
 	 * least some progress on hugification even at worst case.
 	 */
-	while (hpa_try_hugify(tsdn, shard) && nops < max_ops) {
+	while (init_system_thp_mode == thp_mode_default &&
+	       hpa_try_hugify(tsdn, shard) && nops < max_ops) {
 		malloc_mutex_assert_owner(tsdn, &shard->mtx);
 		nops++;
 	}