Merge pull request #5636 from jsternberg/unroll-prune-loop

cache: convert prune loop from recursive invocation to iterative

cache/manager.go

@@ -1012,7 +1012,7 @@ func (cm *cacheManager) Prune(ctx context.Context, ch chan client.UsageInfo, opt
 	cm.muPrune.Lock()
 
 	for _, opt := range opts {
-		if err := cm.pruneOnce(ctx, ch, opt); err != nil {
+		if err := cm.prune(ctx, ch, opt); err != nil {
 			cm.muPrune.Unlock()
 			return err
 		}
@@ -1029,7 +1029,7 @@ func (cm *cacheManager) Prune(ctx context.Context, ch chan client.UsageInfo, opt
 	return nil
 }
 
-func (cm *cacheManager) pruneOnce(ctx context.Context, ch chan client.UsageInfo, opt client.PruneInfo) error {
+func (cm *cacheManager) prune(ctx context.Context, ch chan client.UsageInfo, opt client.PruneInfo) error {
 	filter, err := filters.ParseAll(opt.Filter...)
 	if err != nil {
 		return errors.Wrapf(err, "failed to parse prune filters %v", opt.Filter)
@@ -1066,14 +1066,21 @@ func (cm *cacheManager) pruneOnce(ctx context.Context, ch chan client.UsageInfo,
 		}
 	}
 
-	return cm.prune(ctx, ch, pruneOpt{
+	popt := pruneOpt{
 		filter:       filter,
 		all:          opt.All,
 		checkShared:  check,
 		keepDuration: opt.KeepDuration,
 		keepBytes:    calculateKeepBytes(totalSize, dstat, opt),
 		totalSize:    totalSize,
-	})
+	}
+	for {
+		releasedSize, releasedCount, err := cm.pruneOnce(ctx, ch, popt)
+		if err != nil || releasedCount == 0 {
+			return err
+		}
+		popt.totalSize -= releasedSize
+	}
 }
 
 func calculateKeepBytes(totalSize int64, dstat disk.DiskStat, opt client.PruneInfo) int64 {
@@ -1100,9 +1107,9 @@ func calculateKeepBytes(totalSize int64, dstat disk.DiskStat, opt client.PruneIn
 	return keepBytes
 }
 
-func (cm *cacheManager) prune(ctx context.Context, ch chan client.UsageInfo, opt pruneOpt) (err error) {
+func (cm *cacheManager) pruneOnce(ctx context.Context, ch chan client.UsageInfo, opt pruneOpt) (releasedSize, releasedCount int64, err error) {
 	if opt.keepBytes != 0 && opt.totalSize < opt.keepBytes {
-		return nil
+		return 0, 0, nil
 	}
 
 	var toDelete []*deleteRecord
@@ -1206,11 +1213,11 @@ func (cm *cacheManager) prune(ctx context.Context, ch chan client.UsageInfo, opt
 			// mark metadata as deleted in case we crash before cleanup finished
 			if err := cr.queueDeleted(); err != nil {
 				releaseLocks()
-				return err
+				return 0, 0, err
 			}
 			if err := cr.commitMetadata(); err != nil {
 				releaseLocks()
-				return err
+				return 0, 0, err
 			}
 		}
 		cr.mu.Unlock()
@@ -1221,7 +1228,7 @@ func (cm *cacheManager) prune(ctx context.Context, ch chan client.UsageInfo, opt
 	cm.mu.Unlock()
 
 	if len(toDelete) == 0 {
-		return nil
+		return 0, 0, nil
 	}
 
 	// calculate sizes here so that lock does not need to be held for slow process
@@ -1234,7 +1241,7 @@ func (cm *cacheManager) prune(ctx context.Context, ch chan client.UsageInfo, opt
 		if size == sizeUnknown {
 			// calling size will warm cache for next call
 			if _, err := cr.size(ctx); err != nil {
-				return err
+				return 0, 0, err
 			}
 		}
 	}
@@ -1277,15 +1284,18 @@ func (cm *cacheManager) prune(ctx context.Context, ch chan client.UsageInfo, opt
 			c.Size = cr.equalImmutable.getSize() // benefit from DiskUsage calc
 		}
 
-		opt.totalSize -= c.Size
+		releasedSize += c.Size
 
 		if cr.equalImmutable != nil {
 			if err1 := cr.equalImmutable.remove(ctx, false); err == nil {
 				err = err1
 			}
 		}
-		if err1 := cr.remove(ctx, true); err == nil {
+
+		if err1 := cr.remove(ctx, true); err1 != nil && err == nil {
 			err = err1
+		} else if err1 == nil {
+			releasedCount++
 		}
 
 		if err == nil && ch != nil {
@@ -1294,16 +1304,17 @@ func (cm *cacheManager) prune(ctx context.Context, ch chan client.UsageInfo, opt
 		cr.mu.Unlock()
 	}
 	cm.mu.Unlock()
+
 	if err != nil {
-		return err
+		return releasedSize, releasedCount, err
 	}
 
 	select {
 	case <-ctx.Done():
-		return context.Cause(ctx)
+		err = context.Cause(ctx)
 	default:
-		return cm.prune(ctx, ch, opt)
 	}
+	return releasedSize, releasedCount, err
 }
 
 func (cm *cacheManager) markShared(m map[string]*cacheUsageInfo) error {

control/control.go

@@ -623,14 +623,12 @@ func (c *Controller) gc() {
 	}()
 
 	for _, w := range workers {
-		func(w worker.Worker) {
-			eg.Go(func() error {
-				if policy := w.GCPolicy(); len(policy) > 0 {
-					return w.Prune(ctx, ch, policy...)
-				}
-				return nil
-			})
-		}(w)
+		eg.Go(func() error {
+			if policy := w.GCPolicy(); len(policy) > 0 {
+				return w.Prune(ctx, ch, policy...)
+			}
+			return nil
+		})
 	}
 
 	err = eg.Wait()

hack/composefiles/compose.yaml

@@ -4,16 +4,13 @@ services:
     container_name: buildkit-dev
     build:
       context: ../..
-      args:
-        BUILDKIT_DEBUG: 1
     image: moby/buildkit:local
     ports:
       - 127.0.0.1:5000:5000
       - 127.0.0.1:6060:6060
     restart: always
     privileged: true
     environment:
-      DELVE_PORT: 5000
       OTEL_SERVICE_NAME: buildkitd
       OTEL_EXPORTER_OTLP_ENDPOINT: http://otel-collector:4317
     configs: