diff --git a/manager.go b/manager.go
index 0c18645ac..0cd081d92 100644
--- a/manager.go
+++ b/manager.go
@@ -208,7 +208,7 @@ func (m *Manager) ReadPiece(ctx context.Context, sink io.Writer, sector abi.Sect
 
 	var selector WorkerSelector
 	if len(best) == 0 { // new
-		selector, err = newAllocSelector(ctx, m.index, stores.FTUnsealed, stores.PathSealing)
+		selector = newAllocSelector(ctx, m.index, stores.FTUnsealed, stores.PathSealing)
 	} else { // append to existing
 		selector, err = newExistingSelector(ctx, m.index, sector, stores.FTUnsealed, false)
 	}
@@ -269,7 +269,7 @@ func (m *Manager) AddPiece(ctx context.Context, sector abi.SectorID, existingPie
 	var selector WorkerSelector
 	var err error
 	if len(existingPieces) == 0 { // new
-		selector, err = newAllocSelector(ctx, m.index, stores.FTUnsealed, stores.PathSealing)
+		selector = newAllocSelector(ctx, m.index, stores.FTUnsealed, stores.PathSealing)
 	} else { // use existing
 		selector, err = newExistingSelector(ctx, m.index, sector, stores.FTUnsealed, false)
 	}
@@ -300,10 +300,7 @@ func (m *Manager) SealPreCommit1(ctx context.Context, sector abi.SectorID, ticke
 
 	// TODO: also consider where the unsealed data sits
 
-	selector, err := newAllocSelector(ctx, m.index, stores.FTCache|stores.FTSealed, stores.PathSealing)
-	if err != nil {
-		return nil, xerrors.Errorf("creating path selector: %w", err)
-	}
+	selector := newAllocSelector(ctx, m.index, stores.FTCache|stores.FTSealed, stores.PathSealing)
 
 	err = m.sched.Schedule(ctx, sector, sealtasks.TTPreCommit1, selector, schedFetch(sector, stores.FTUnsealed, stores.PathSealing, stores.AcquireMove), func(ctx context.Context, w Worker) error {
 		p, err := w.SealPreCommit1(ctx, sector, ticket, pieces)
@@ -417,11 +414,7 @@ func (m *Manager) FinalizeSector(ctx context.Context, sector abi.SectorID, keepU
 		return err
 	}
 
-	fetchSel, err := newAllocSelector(ctx, m.index, stores.FTCache|stores.FTSealed, stores.PathStorage)
-	if err != nil {
-		return xerrors.Errorf("creating fetchSel: %w", err)
-	}
-
+	fetchSel := newAllocSelector(ctx, m.index, stores.FTCache|stores.FTSealed, stores.PathStorage)
 	moveUnsealed := unsealed
 	{
 		if len(keepUnsealed) == 0 {
diff --git a/sched_test.go b/sched_test.go
index d0d0e7ca9..e810b6a0d 100644
--- a/sched_test.go
+++ b/sched_test.go
@@ -2,9 +2,21 @@ package sectorstorage
 
 import (
 	"context"
+	"io"
+	"sync"
 	"testing"
+	"time"
 
+	"github.com/ipfs/go-cid"
 	"github.com/stretchr/testify/require"
+
+	"github.com/filecoin-project/specs-actors/actors/abi"
+
+	"github.com/filecoin-project/sector-storage/fsutil"
+	"github.com/filecoin-project/sector-storage/sealtasks"
+	"github.com/filecoin-project/sector-storage/stores"
+	"github.com/filecoin-project/sector-storage/storiface"
+	"github.com/filecoin-project/specs-storage/storage"
 )
 
 func TestWithPriority(t *testing.T) {
@@ -16,3 +28,399 @@ func TestWithPriority(t *testing.T) {
 
 	require.Equal(t, 2222, getPriority(ctx))
 }
+
+type schedTestWorker struct {
+	name string
+	taskTypes map[sealtasks.TaskType]struct{}
+	paths []stores.StoragePath
+
+	closed bool
+	closing chan struct{}
+}
+
+func (s *schedTestWorker) SealPreCommit1(ctx context.Context, sector abi.SectorID, ticket abi.SealRandomness, pieces []abi.PieceInfo) (storage.PreCommit1Out, error) {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) SealPreCommit2(ctx context.Context, sector abi.SectorID, pc1o storage.PreCommit1Out) (storage.SectorCids, error) {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) SealCommit1(ctx context.Context, sector abi.SectorID, ticket abi.SealRandomness, seed abi.InteractiveSealRandomness, pieces []abi.PieceInfo, cids storage.SectorCids) (storage.Commit1Out, error) {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) SealCommit2(ctx context.Context, sector abi.SectorID, c1o storage.Commit1Out) (storage.Proof, error) {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) FinalizeSector(ctx context.Context, sector abi.SectorID, keepUnsealed []storage.Range) error {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) ReleaseUnsealed(ctx context.Context, sector abi.SectorID, safeToFree []storage.Range) error {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) Remove(ctx context.Context, sector abi.SectorID) error {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) NewSector(ctx context.Context, sector abi.SectorID) error {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) AddPiece(ctx context.Context, sector abi.SectorID, pieceSizes []abi.UnpaddedPieceSize, newPieceSize abi.UnpaddedPieceSize, pieceData storage.Data) (abi.PieceInfo, error) {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) MoveStorage(ctx context.Context, sector abi.SectorID) error {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) Fetch(ctx context.Context, id abi.SectorID, ft stores.SectorFileType, ptype stores.PathType, am stores.AcquireMode) error {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) UnsealPiece(ctx context.Context, id abi.SectorID, index storiface.UnpaddedByteIndex, size abi.UnpaddedPieceSize, randomness abi.SealRandomness, cid cid.Cid) error {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) ReadPiece(ctx context.Context, writer io.Writer, id abi.SectorID, index storiface.UnpaddedByteIndex, size abi.UnpaddedPieceSize) error {
+	panic("implement me")
+}
+
+func (s *schedTestWorker) TaskTypes(ctx context.Context) (map[sealtasks.TaskType]struct{}, error) {
+	return s.taskTypes, nil
+}
+
+func (s *schedTestWorker) Paths(ctx context.Context) ([]stores.StoragePath, error) {
+	return s.paths, nil
+}
+
+func (s *schedTestWorker) Info(ctx context.Context) (storiface.WorkerInfo, error) {
+	return storiface.WorkerInfo{
+		Hostname:  s.name,
+		Resources: storiface.WorkerResources{
+			MemPhysical: 128 << 30,
+			MemSwap:     200 << 30,
+			MemReserved: 2 << 30,
+			CPUs:        32,
+			GPUs:        []string{"a GPU"},
+		},
+	}, nil
+}
+
+func (s *schedTestWorker) Closing(ctx context.Context) (<-chan struct{}, error) {
+	return s.closing, nil
+}
+
+func (s *schedTestWorker) Close() error {
+	if !s.closed {
+		s.closed = true
+		close(s.closing)
+	}
+	return nil
+}
+
+var _ Worker = &schedTestWorker{}
+
+func addTestWorker(t *testing.T, sched *scheduler, index *stores.Index, name string, taskTypes map[sealtasks.TaskType]struct{}) {
+	w := &schedTestWorker{
+		name:    name,
+		taskTypes: taskTypes,
+		paths: []stores.StoragePath{{ID: "bb-8", Weight: 2, LocalPath: "<octopus>food</octopus>", CanSeal: true, CanStore: true}},
+
+		closing: make(chan struct{}),
+	}
+
+	for _, path := range w.paths {
+		err := index.StorageAttach(context.TODO(), stores.StorageInfo{
+			ID:            path.ID,
+			URLs:          nil,
+			Weight:        path.Weight,
+			CanSeal:       path.CanSeal,
+			CanStore:      path.CanStore,
+		}, fsutil.FsStat{
+			Capacity:  1 << 40,
+			Available: 1 << 40,
+			Reserved:  3,
+		})
+		require.NoError(t, err)
+	}
+
+	info, err := w.Info(context.TODO())
+	require.NoError(t, err)
+
+	sched.newWorkers <- &workerHandle{
+		w:         w,
+		info:      info,
+		preparing: &activeResources{},
+		active:    &activeResources{},
+	}
+}
+
+func TestSchedStartStop(t *testing.T) {
+	spt := abi.RegisteredSealProof_StackedDrg32GiBV1
+	sched := newScheduler(spt)
+	go sched.runSched()
+
+	addTestWorker(t, sched, stores.NewIndex(), "fred", nil)
+
+	sched.schedClose()
+}
+
+func TestSched(t *testing.T) {
+	ctx := context.Background()
+	spt := abi.RegisteredSealProof_StackedDrg32GiBV1
+
+	sectorAte := abi.SectorID{
+		Miner:  8,
+		Number: 8,
+	}
+
+	type workerSpec struct {
+		name string
+		taskTypes map[sealtasks.TaskType]struct{}
+	}
+
+	noopPrepare := func(ctx context.Context, w Worker) error {
+		return nil
+	}
+
+	type runMeta struct {
+		done map[string]chan struct{}
+
+		wg sync.WaitGroup
+	}
+
+	type task func(*testing.T, *scheduler, *stores.Index, *runMeta)
+
+	sched := func(taskName, expectWorker string, taskType sealtasks.TaskType) task {
+		return func(t *testing.T, sched *scheduler, index *stores.Index, rm *runMeta) {
+			done := make(chan struct{})
+			rm.done[taskName] = done
+
+			sel := newAllocSelector(ctx, index, stores.FTCache, stores.PathSealing)
+
+			rm.wg.Add(1)
+			go func() {
+				defer rm.wg.Done()
+
+				err := sched.Schedule(ctx, sectorAte, taskType, sel, noopPrepare, func(ctx context.Context, w Worker) error {
+					wi, err := w.Info(ctx)
+					require.NoError(t, err)
+
+					require.Equal(t, expectWorker, wi.Hostname)
+
+					log.Info("IN  ", taskName)
+
+					for {
+						_, ok := <-done
+						if !ok {
+							break
+						}
+					}
+
+					log.Info("OUT ", taskName)
+
+					return nil
+				})
+				require.NoError(t, err)
+			}()
+		}
+	}
+
+	taskStarted := func(name string) task {
+		return func(t *testing.T, sched *scheduler, index *stores.Index, rm *runMeta) {
+			rm.done[name] <- struct{}{}
+		}
+	}
+
+	taskDone := func(name string) task {
+		return func(t *testing.T, sched *scheduler, index *stores.Index, rm *runMeta) {
+			rm.done[name] <- struct{}{}
+			close(rm.done[name])
+		}
+	}
+
+	taskNotScheduled := func(name string) task {
+		return func(t *testing.T, sched *scheduler, index *stores.Index, rm *runMeta) {
+			select {
+			case rm.done[name] <- struct{}{}:
+				t.Fatal("not expected")
+			case <-time.After(10 * time.Millisecond): // TODO: better synchronization thingy
+			}
+		}
+	}
+
+	testFunc := func(workers []workerSpec, tasks []task) func(t *testing.T) {
+		return func(t *testing.T) {
+			index := stores.NewIndex()
+
+			sched := newScheduler(spt)
+			go sched.runSched()
+
+			for _, worker := range workers {
+				addTestWorker(t, sched, index, worker.name, worker.taskTypes)
+			}
+
+			rm := runMeta{
+				done: map[string]chan struct{}{},
+			}
+
+			for _, task := range tasks {
+				task(t, sched, index, &rm)
+			}
+
+			log.Info("wait for async stuff")
+			rm.wg.Wait()
+
+			sched.schedClose()
+		}
+	}
+
+	multTask := func(tasks ...task) task {
+		return func(t *testing.T, s *scheduler, index *stores.Index, meta *runMeta) {
+			for _, tsk := range tasks {
+				tsk(t, s, index, meta)
+			}
+		}
+	}
+
+	t.Run("one-pc1", testFunc([]workerSpec{
+		{name: "fred", taskTypes: map[sealtasks.TaskType]struct{}{sealtasks.TTPreCommit1:{}}},
+	}, []task{
+		sched("pc1-1", "fred", sealtasks.TTPreCommit1),
+		taskDone("pc1-1"),
+	}))
+
+	t.Run("pc1-2workers-1", testFunc([]workerSpec{
+		{name: "fred2", taskTypes: map[sealtasks.TaskType]struct{}{sealtasks.TTPreCommit2:{}}},
+		{name: "fred1", taskTypes: map[sealtasks.TaskType]struct{}{sealtasks.TTPreCommit1:{}}},
+	}, []task{
+		sched("pc1-1", "fred1", sealtasks.TTPreCommit1),
+		taskDone("pc1-1"),
+	}))
+
+	t.Run("pc1-2workers-2", testFunc([]workerSpec{
+		{name: "fred1", taskTypes: map[sealtasks.TaskType]struct{}{sealtasks.TTPreCommit1:{}}},
+		{name: "fred2", taskTypes: map[sealtasks.TaskType]struct{}{sealtasks.TTPreCommit2:{}}},
+	}, []task{
+		sched("pc1-1", "fred1", sealtasks.TTPreCommit1),
+		taskDone("pc1-1"),
+	}))
+
+	t.Run("pc1-block-pc2", testFunc([]workerSpec{
+		{name: "fred", taskTypes: map[sealtasks.TaskType]struct{}{sealtasks.TTPreCommit1:{}, sealtasks.TTPreCommit2:{}}},
+	}, []task{
+		sched("pc1", "fred", sealtasks.TTPreCommit1),
+		taskStarted("pc1"),
+
+		sched("pc2", "fred", sealtasks.TTPreCommit2),
+		taskNotScheduled("pc2"),
+
+		taskDone("pc1"),
+		taskDone("pc2"),
+	}))
+
+	t.Run("pc2-block-pc1", testFunc([]workerSpec{
+		{name: "fred", taskTypes: map[sealtasks.TaskType]struct{}{sealtasks.TTPreCommit1:{}, sealtasks.TTPreCommit2:{}}},
+	}, []task{
+		sched("pc2", "fred", sealtasks.TTPreCommit2),
+		taskStarted("pc2"),
+
+		sched("pc1", "fred", sealtasks.TTPreCommit1),
+		taskNotScheduled("pc1"),
+
+		taskDone("pc2"),
+		taskDone("pc1"),
+	}))
+
+	t.Run("pc1-batching", testFunc([]workerSpec{
+		{name: "fred", taskTypes: map[sealtasks.TaskType]struct{}{sealtasks.TTPreCommit1:{}}},
+	}, []task{
+		sched("t1", "fred", sealtasks.TTPreCommit1),
+		taskStarted("t1"),
+
+		sched("t2", "fred", sealtasks.TTPreCommit1),
+		taskStarted("t2"),
+
+		// with worker settings, we can only run 2 parallel PC1s
+
+		// start 2 more to fill fetch buffer
+
+		sched("t3", "fred", sealtasks.TTPreCommit1),
+		taskNotScheduled("t3"),
+
+		sched("t4", "fred", sealtasks.TTPreCommit1),
+		taskNotScheduled("t4"),
+
+		taskDone("t1"),
+		taskDone("t2"),
+
+		taskStarted("t3"),
+		taskStarted("t4"),
+
+		taskDone("t3"),
+		taskDone("t4"),
+	}))
+
+	twoPC1 := func(prefix string, schedAssert func(name string) task) task {
+		return multTask(
+			sched(prefix + "-a", "fred", sealtasks.TTPreCommit1),
+			schedAssert(prefix + "-a"),
+
+			sched(prefix + "-b", "fred", sealtasks.TTPreCommit1),
+			schedAssert(prefix + "-b"),
+			)
+	}
+
+	twoPC1Done := func(prefix string) task {
+		return multTask(
+			taskDone(prefix + "-1"),
+			taskDone(prefix + "-b"),
+			)
+	}
+
+	t.Run("pc1-pc2-prio", testFunc([]workerSpec{
+		{name: "fred", taskTypes: map[sealtasks.TaskType]struct{}{sealtasks.TTPreCommit1:{}, sealtasks.TTPreCommit2: {}}},
+	}, []task{
+		// fill exec/fetch buffers
+		twoPC1("w0", taskStarted),
+		twoPC1("w1", taskNotScheduled),
+
+		// fill worker windows
+		twoPC1("w2", taskNotScheduled),
+		twoPC1("w3", taskNotScheduled),
+
+		// windowed
+
+		sched("t1", "fred", sealtasks.TTPreCommit1),
+		taskNotScheduled("t1"),
+
+		sched("t2", "fred", sealtasks.TTPreCommit1),
+		taskNotScheduled("t2"),
+
+		sched("t3", "fred", sealtasks.TTPreCommit2),
+		taskNotScheduled("t3"),
+
+		twoPC1Done("w0"),
+		twoPC1Done("w1"),
+		twoPC1Done("w2"),
+		twoPC1Done("w3"),
+
+		taskStarted("t1"),
+		taskNotScheduled("t2"),
+		taskNotScheduled("t3"),
+
+		taskDone("t1"),
+
+		taskStarted("t2"),
+		taskStarted("t3"),
+
+		taskDone("t2"),
+		taskDone("t3"),
+	}))
+}
+
diff --git a/selector_alloc.go b/selector_alloc.go
index 874bf7bb0..53e121737 100644
--- a/selector_alloc.go
+++ b/selector_alloc.go
@@ -17,12 +17,12 @@ type allocSelector struct {
 	ptype stores.PathType
 }
 
-func newAllocSelector(ctx context.Context, index stores.SectorIndex, alloc stores.SectorFileType, ptype stores.PathType) (*allocSelector, error) {
+func newAllocSelector(ctx context.Context, index stores.SectorIndex, alloc stores.SectorFileType, ptype stores.PathType) (*allocSelector) {
 	return &allocSelector{
 		index: index,
 		alloc: alloc,
 		ptype: ptype,
-	}, nil
+	}
 }
 
 func (s *allocSelector) Ok(ctx context.Context, task sealtasks.TaskType, spt abi.RegisteredSealProof, whnd *workerHandle) (bool, error) {