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 30d9c5e..95bc80b 100644 (file)
--- 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 *