From ebdbbfb3b5ee13277e808f4f55672858557ef090 Mon Sep 17 00:00:00 2001
From: Alexander Motin <mav@FreeBSD.org>
Date: Mon, 12 Oct 2015 14:27:27 +0000
Subject: [PATCH] 6281 prefetching should apply to 1MB reads

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Alexander Motin <mav@freebsd.org>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Justin Gibbs <gibbs@scsiguy.com>
Reviewed by: Xin Li <delphij@freebsd.org>
Approved by: Gordon Ross <gordon.ross@nexenta.com>
Author: George Wilson <george.wilson@delphix.com>

illumos/illumos-gate@632802744ef6d17e06d6980a95f631615c3b060f
---
 uts/common/fs/zfs/dmu.c        | 2 +-
 uts/common/fs/zfs/dmu_zfetch.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/uts/common/fs/zfs/dmu.c b/uts/common/fs/zfs/dmu.c
index 4b02f75d4f7a..6ebd95cd3ef2 100644
--- a/uts/common/fs/zfs/dmu.c
+++ b/uts/common/fs/zfs/dmu.c
@@ -442,7 +442,7 @@ dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
 	}
 
 	if ((flags & DMU_READ_NO_PREFETCH) == 0 && read &&
-	    length < zfetch_array_rd_sz) {
+	    length <= zfetch_array_rd_sz) {
 		dmu_zfetch(&dn->dn_zfetch, blkid, nblks);
 	}
 	rw_exit(&dn->dn_struct_rwlock);
diff --git a/uts/common/fs/zfs/dmu_zfetch.c b/uts/common/fs/zfs/dmu_zfetch.c
index b05e8f0cf2e4..f2cdf863d83c 100644
--- a/uts/common/fs/zfs/dmu_zfetch.c
+++ b/uts/common/fs/zfs/dmu_zfetch.c
@@ -24,7 +24,7 @@
  */
 
 /*
- * Copyright (c) 2013, 2014 by Delphix. All rights reserved.
+ * Copyright (c) 2013, 2015 by Delphix. All rights reserved.
  */
 
 #include <sys/zfs_context.h>
@@ -49,7 +49,7 @@ uint32_t	zfetch_max_streams = 8;
 uint32_t	zfetch_min_sec_reap = 2;
 /* max bytes to prefetch per stream (default 8MB) */
 uint32_t	zfetch_max_distance = 8 * 1024 * 1024;
-/* number of bytes in a array_read at which we stop prefetching (1MB) */
+/* max number of bytes in an array_read in which we allow prefetching (1MB) */
 uint64_t	zfetch_array_rd_sz = 1024 * 1024;
 
 typedef struct zfetch_stats {