From: beck <beck@openbsd.org>
Date: Tue, 18 Apr 2017 13:41:32 +0000 (+0000)
Subject: ensure the buffer cache backs off all the way with the correct type
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=c48a3f33ba7aa257248afd95ea073cc8ab935ec3;p=openbsd

ensure the buffer cache backs off all the way with the correct type
of memory, handling the fact that both queues are actually in dma
space when not flipping buffers high
---

diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index 30d9c5eb4fc..95bc80bc0e6 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfs_bio.c,v 1.181 2017/04/16 14:25:42 beck Exp $	*/
+/*	$OpenBSD: vfs_bio.c,v 1.182 2017/04/18 13:41:32 beck Exp $	*/
 /*	$NetBSD: vfs_bio.c,v 1.44 1996/06/11 11:15:36 pk Exp $	*/
 
 /*
@@ -1507,13 +1507,17 @@ bufcache_getcleanbuf_range(int start, int end, int discard)
 struct buf *
 bufcache_gethighcleanbuf(void)
 {
-	return bufcache_getcleanbuf_range(DMA_CACHE + 1, NUM_CACHES -1, 0);
+	if (!fliphigh)
+		return NULL;
+	return bufcache_getcleanbuf_range(DMA_CACHE + 1, NUM_CACHES - 1, 0);
 }
 
 struct buf *
 bufcache_getdmacleanbuf(void)
 {
-	return bufcache_getcleanbuf_range(DMA_CACHE, DMA_CACHE, 0);
+	if (fliphigh)
+		return bufcache_getcleanbuf_range(DMA_CACHE, DMA_CACHE, 0);
+	return bufcache_getcleanbuf_range(DMA_CACHE, NUM_CACHES - 1, 0);
 }
 
 struct buf *