More rotors, such that more categories of allocation targets can be d…

…ifferentiated.

Assign rotor vector categories based on pool property config instead of module parameters.

include/sys/metaslab_impl.h

@@ -67,7 +67,7 @@ extern "C" {
  * big and less expensive.  Depending on the size of an allocation,
  * a vdev will be chosen.
  */
-#define	METASLAB_CLASS_ROTORS	2
+#define	METASLAB_CLASS_ROTORS	5
 
 struct metaslab_class {
 	kmutex_t		mc_lock;

module/zfs/metaslab.c

@@ -102,12 +102,6 @@ int zfs_mg_noalloc_threshold = 0;
  */
 int zfs_mg_fragmentation_threshold = 85;
 
-/*
- * Allocate from faster vdev in pool if below threshold, allocate
- * from slower vdev in pool if above threshold.
- */
-int zfs_metaslab_mixed_slowsize_threshold = 0;
-
 /*
  * Allow metaslabs to keep their active state as long as their fragmentation
  * percentage is less than or equal to zfs_metaslab_fragmentation_threshold. An
@@ -580,6 +574,22 @@ metaslab_group_alloc_update(metaslab_group_t *mg)
 	mutex_exit(&mg->mg_lock);
 }
 
+/*
+ * Five categories, from faster to slower:
+ *
+ * 0: nonrot (SSD)      disk or mirror
+ * 1: nonrot (SSD)      raidz
+ * 2: mixed nonrot+rot  anything (raidz makes little sense)
+ * 3: rot (HDD)         disk or mirror
+ * 4: rot (HDD)         raidz
+ */
+
+#define	METASLAB_ROTOR_VDEV_TYPE_SSD		0x01
+#define	METASLAB_ROTOR_VDEV_TYPE_SSD_RAIDZ	0x02
+#define	METASLAB_ROTOR_VDEV_TYPE_MIXED		0x04
+#define	METASLAB_ROTOR_VDEV_TYPE_HDD		0x08
+#define	METASLAB_ROTOR_VDEV_TYPE_HDD_RAIDZ	0x10
+
 /*
  * Please do not judge the rotor vector approach based on the ugliness
  * of this parsing routine.  :-)
@@ -657,15 +667,20 @@ metaslab_parse_rotor_config(metaslab_class_t *mc, char *rotorvector)
 			len = comma-rotorvector;
 
 			if (strncmp(rotorvector, "ssd", len) == 0)
-				mc->mc_rotvec_categories[nrot] |= 0x01;
+				mc->mc_rotvec_categories[nrot] |=
+				    METASLAB_ROTOR_VDEV_TYPE_SSD;
 			else if (strncmp(rotorvector, "ssd-raidz", len) == 0)
-				mc->mc_rotvec_categories[nrot] |= 0x02;
+				mc->mc_rotvec_categories[nrot] |=
+				    METASLAB_ROTOR_VDEV_TYPE_SSD_RAIDZ;
 			else if (strncmp(rotorvector, "mixed", len) == 0)
-				mc->mc_rotvec_categories[nrot] |= 0x04;
+				mc->mc_rotvec_categories[nrot] |=
+				    METASLAB_ROTOR_VDEV_TYPE_MIXED;
 			else if (strncmp(rotorvector, "hdd", len) == 0)
-				mc->mc_rotvec_categories[nrot] |= 0x08;
+				mc->mc_rotvec_categories[nrot] |=
+				    METASLAB_ROTOR_VDEV_TYPE_HDD;
 			else if (strncmp(rotorvector, "hdd-raidz", len) == 0)
-				mc->mc_rotvec_categories[nrot] |= 0x10;
+				mc->mc_rotvec_categories[nrot] |=
+				    METASLAB_ROTOR_VDEV_TYPE_HDD_RAIDZ;
 			else {
 				/* It must be a vdev guid. */
 				uint64_t guid;
@@ -744,25 +759,43 @@ metaslab_parse_rotor_config(metaslab_class_t *mc, char *rotorvector)
 }
 
 int
-metaslab_vdev_rotor_category(vdev_t *vd)
+metaslab_vdev_rotor_category(metaslab_class_t *mc, vdev_t *vd)
 {
-	/*
-	 * Five categories, from faster to slower:
-	 *
-	 * 0: nonrot (SSD)      disk or mirror
-	 * 1: nonrot (SSD)      raidz
-	 * 2: mixed nonrot+rot  anything (raidz makes little sense)
-	 * 3: rot (HDD)         disk or mirror
-	 * 4: rot (HDD)         raidz
-	 */
+	int i, j;
+	int type;
+
+	/* First match on the vdev guid assignments. */
+	for (i = 0; i < METASLAB_CLASS_ROTORS; i++)
+		for (j = 0; j < 5 && mc->mc_rotvec_vdev_guids[i][j]; j++)
+			if (mc->mc_rotvec_vdev_guids[i][j] == vd->vdev_guid)
+				return (i);
+
+	/* Match on the kind of vdev. */
+
+	/* Figure out what kind we are. */
 
 	if (vd->vdev_nonrot) {
-		return ((vd->vdev_ops != &vdev_raidz_ops) ? 0 : 1);
+		type = ((vd->vdev_ops != &vdev_raidz_ops) ?
+		    METASLAB_ROTOR_VDEV_TYPE_SSD :
+		    METASLAB_ROTOR_VDEV_TYPE_SSD_RAIDZ);
 	} else if (vd->vdev_nonrot_mix) {
-		return (2);
+		type = METASLAB_ROTOR_VDEV_TYPE_MIXED;
 	} else {
-		return ((vd->vdev_ops != &vdev_raidz_ops) ? 3 : 4);
+		type = ((vd->vdev_ops != &vdev_raidz_ops) ?
+		    METASLAB_ROTOR_VDEV_TYPE_HDD :
+		    METASLAB_ROTOR_VDEV_TYPE_HDD_RAIDZ);
 	}
+
+	for (i = 0; i < METASLAB_CLASS_ROTORS; i++)
+		if (mc->mc_rotvec_categories[i] & type)
+			return (i);
+
+	/* Assign to last category, i.e. with a (dummy) zero limit. */
+	for (i = 0; i < METASLAB_CLASS_ROTORS; i++)
+		if (mc->mc_rotvec_threshold[i] == 0)
+			return (i);
+
+	return (METASLAB_CLASS_ROTORS-1);
 }
 
 metaslab_group_t *
@@ -810,6 +843,8 @@ metaslab_group_destroy(metaslab_group_t *mg)
 void
 metaslab_group_set_rotor_category(metaslab_group_t *mg, boolean_t failed_dev)
 {
+	metaslab_class_t *mc = mg->mg_class;
+
 	/* Already done? */
 	if (mg->mg_nrot != -1)
 		return;
@@ -824,11 +859,8 @@ metaslab_group_set_rotor_category(metaslab_group_t *mg, boolean_t failed_dev)
 	 */
 	if (failed_dev)
 		mg->mg_nrot = METASLAB_CLASS_ROTORS-1;
-	else {
-		mg->mg_nrot = 0;
-		if (!mg->mg_vd->vdev_nonrot)
-			mg->mg_nrot = 1;
-	}
+	else
+		mg->mg_nrot = metaslab_vdev_rotor_category(mc, mg->mg_vd);
 }
 
 void
@@ -2675,13 +2707,10 @@ metaslab_alloc_dva(spa_t *spa, metaslab_class_t *mc, uint64_t psize,
 	 */
 	nrot = 0;
 
-	if (zfs_metaslab_mixed_slowsize_threshold) {
-		if (psize >= zfs_metaslab_mixed_slowsize_threshold) {
-			nrot = 1;
-
-			if (nrot > mc->mc_max_nrot)
-				nrot = mc->mc_max_nrot;
-		}
+	while (nrot < mc->mc_max_nrot) {
+		if (psize < mc->mc_rotvec_threshold[nrot])
+			break; /* Size below threshold, accept. */
+		nrot++;
 	}
 
 	for (; nrot < METASLAB_CLASS_ROTORS; nrot++)
@@ -3331,10 +3360,6 @@ module_param(zfs_mg_fragmentation_threshold, int, 0644);
 MODULE_PARM_DESC(zfs_mg_fragmentation_threshold,
 	"fragmentation for metaslab group to allow allocation");
 
-module_param(zfs_metaslab_mixed_slowsize_threshold, int, 0644);
-MODULE_PARM_DESC(zfs_metaslab_mixed_slowsize_threshold,
-	"size threshold to choose slower (rotating) storage in mixed pool");
-
 module_param(zfs_metaslab_fragmentation_threshold, int, 0644);
 MODULE_PARM_DESC(zfs_metaslab_fragmentation_threshold,
 	"fragmentation for metaslab to allow allocation");