From c0fa4d575922c9f1cafccbb4a41ae40d471a0509 Mon Sep 17 00:00:00 2001
From: deraadt <deraadt@openbsd.org>
Date: Thu, 8 Feb 2018 09:42:48 +0000
Subject: [PATCH] After flushing disks, try again to release all memory.  We
 don't need to save dirty memory to the hibernate space.

---
 sys/dev/acpi/acpi.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/sys/dev/acpi/acpi.c b/sys/dev/acpi/acpi.c
index 375505c7e1b..ea23d66040a 100644
--- a/sys/dev/acpi/acpi.c
+++ b/sys/dev/acpi/acpi.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: acpi.c,v 1.337 2018/02/08 09:37:17 deraadt Exp $ */
+/* $OpenBSD: acpi.c,v 1.338 2018/02/08 09:42:48 deraadt Exp $ */
 /*
  * Copyright (c) 2005 Thorsten Lockert <tholo@sigmasoft.com>
  * Copyright (c) 2005 Jordan Hargrave <jordan@openbsd.org>
@@ -2512,6 +2512,18 @@ acpi_sleep_state(struct acpi_softc *sc, int sleepmode)
 	acpi_sleep_mp();
 #endif
 
+#ifdef HIBERNATE
+	if (sleepmode == ACPI_SLEEP_HIBERNATE) {
+		/*
+		 * We've just done various forms of syncing to disk
+		 * churned lots of memory dirty.  We don't need to
+		 * save that dirty memory to hibernate, so release it.
+		 */
+		hibernate_suspend_bufcache();
+		uvmpd_hibernate();
+	}
+#endif /* HIBERNATE */
+
 	resettodr();
 
 	s = splhigh();
-- 
2.20.1