Pool allocation classes

Allocation Classes add the ability to have allocation classes in a
pool that are dedicated to serving specific block categories, such
as DDT data, metadata, and small file blocks. A pool can opt-in to
this feature by adding a 'special' or 'dedup' top-level VDEV.

Reviewed by: Pavel Zakharov <[email protected]>
Reviewed-by: Richard Laager <[email protected]>
Reviewed-by: Alek Pinchuk <[email protected]>
Reviewed-by: Håkan Johansson <[email protected]>
Reviewed-by: Andreas Dilger <[email protected]>
Reviewed-by: DHE <[email protected]>
Reviewed-by: Richard Elling <[email protected]>
Reviewed-by: Gregor Kopka <[email protected]>
Reviewed-by: Kash Pande <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Matthew Ahrens <[email protected]>
Signed-off-by: Don Brady <[email protected]>
Closes #5182 

1 files changed, 10 insertions, 0 deletions

diff --git a/include/sys/vdev_impl.h b/include/sys/vdev_impl.h
index 701328ea6..e055161e8 100644
--- a/include/sys/vdev_impl.h
+++ b/include/sys/vdev_impl.h
@@ -21,6 +21,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2011, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2017, Intel Corporation.
  */
 
 #ifndef _SYS_VDEV_IMPL_H
@@ -140,6 +141,14 @@ struct vdev_queue {
 	kmutex_t	vq_lock;
 };
 
+typedef enum vdev_alloc_bias {
+	VDEV_BIAS_NONE,
+	VDEV_BIAS_LOG,		/* dedicated to ZIL data (SLOG) */
+	VDEV_BIAS_SPECIAL,	/* dedicated to ddt, metadata, and small blks */
+	VDEV_BIAS_DEDUP		/* dedicated to dedup metadata */
+} vdev_alloc_bias_t;
+
+
 /*
  * On-disk indirect vdev state.
  *
@@ -236,6 +245,7 @@ struct vdev {
 	boolean_t	vdev_ishole;	/* is a hole in the namespace	*/
 	kmutex_t	vdev_queue_lock; /* protects vdev_queue_depth	*/
 	uint64_t	vdev_top_zap;
+	vdev_alloc_bias_t vdev_alloc_bias; /* metaslab allocation bias	*/
 
 	/* pool checkpoint related */
 	space_map_t	*vdev_checkpoint_sm;	/* contains reserved blocks */