From bff19560ee234a58064ae6bc4645d29d9e02e5a5 Mon Sep 17 00:00:00 2001
From: Edward Tomasz Napierala <trasz@FreeBSD.org>
Date: Tue, 23 Oct 2018 13:54:54 +0000
Subject: [PATCH] Pick 676cdd66792ccb629a978837ea2a066d5db342cc from upstream:

    Disable runtime detection of lazy purging support on FreeBSD.

    The check doesn't seem to serve any purpose here, and this shaves
    off three syscalls on binary startup.

Discussed by:	jasone
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
---
 contrib/jemalloc/src/pages.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/contrib/jemalloc/src/pages.c b/contrib/jemalloc/src/pages.c
index 26002692d600..8acebd1b818b 100644
--- a/contrib/jemalloc/src/pages.c
+++ b/contrib/jemalloc/src/pages.c
@@ -588,6 +588,11 @@ pages_boot(void) {
 
 	init_thp_state();
 
+#ifdef __FreeBSD__
+	/*
+	 * FreeBSD doesn't need the check; madvise(2) is known to work.
+	 */
+#else
 	/* Detect lazy purge runtime support. */
 	if (pages_can_purge_lazy) {
 		bool committed = false;
@@ -601,6 +606,7 @@ pages_boot(void) {
 		}
 		os_pages_unmap(madv_free_page, PAGE);
 	}
+#endif
 
 	return false;
 }