From d84b266e99093314cead7381a016bf5062a1fb7c Mon Sep 17 00:00:00 2001
From: kib <kib@FreeBSD.org>
Date: Tue, 19 Dec 2017 10:06:55 +0000
Subject: [PATCH] Perform all accesses to uma_reclaim_needed using atomic(9)
 KPI.

Reviewed by:	alc, jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D13534
---
 sys/vm/uma_core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c
index ee46fcb08e59..81c953a48383 100644
--- a/sys/vm/uma_core.c
+++ b/sys/vm/uma_core.c
@@ -3170,14 +3170,14 @@ uma_reclaim_worker(void *arg __unused)
 
 	for (;;) {
 		sx_xlock(&uma_drain_lock);
-		while (uma_reclaim_needed == 0)
+		while (atomic_load_int(&uma_reclaim_needed) == 0)
 			sx_sleep(uma_reclaim, &uma_drain_lock, PVM, "umarcl",
 			    hz);
 		sx_xunlock(&uma_drain_lock);
 		EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
 		sx_xlock(&uma_drain_lock);
 		uma_reclaim_locked(true);
-		uma_reclaim_needed = 0;
+		atomic_store_int(&uma_reclaim_needed, 0);
 		sx_xunlock(&uma_drain_lock);
 		/* Don't fire more than once per-second. */
 		pause("umarclslp", hz);