syz-manager: preload corpus asynchronously

With load of inputs and slow disk preloading can take
tens of seconds. During that time we don't even serve
web interface, and don't start VMs.
Preload it asynchronously, we need it much later.

1 files changed, 27 insertions, 24 deletions

diff --git a/syz-manager/manager.go b/syz-manager/manager.go
index 87e459270..3f7cb1254 100644
--- a/syz-manager/manager.go
+++ b/syz-manager/manager.go
@@ -48,28 +48,29 @@ var (
 )
 
 type Manager struct {
-	cfg            *mgrconfig.Config
-	vmPool         *vm.Pool
-	target         *prog.Target
-	sysTarget      *targets.Target
-	reporter       *report.Reporter
-	crashdir       string
-	serv           *RPCServer
-	corpus         *corpus.Corpus
-	corpusDB       *db.DB
-	corpusDBMu     sync.Mutex // for concurrent operations on corpusDB
-	startTime      time.Time
-	firstConnect   time.Time
-	fuzzingTime    time.Duration
-	stats          *Stats
-	crashTypes     map[string]bool
-	vmStop         chan bool
-	checkResult    *rpctype.CheckArgs
-	fresh          bool
-	expertMode     bool
-	numFuzzing     uint32
-	numReproducing uint32
-	nextInstanceID atomic.Uint64
+	cfg             *mgrconfig.Config
+	vmPool          *vm.Pool
+	target          *prog.Target
+	sysTarget       *targets.Target
+	reporter        *report.Reporter
+	crashdir        string
+	serv            *RPCServer
+	corpus          *corpus.Corpus
+	corpusDB        *db.DB
+	corpusDBMu      sync.Mutex // for concurrent operations on corpusDB
+	corpusPreloaded chan bool
+	startTime       time.Time
+	firstConnect    time.Time
+	fuzzingTime     time.Duration
+	stats           *Stats
+	crashTypes      map[string]bool
+	vmStop          chan bool
+	checkResult     *rpctype.CheckArgs
+	fresh           bool
+	expertMode      bool
+	numFuzzing      uint32
+	numReproducing  uint32
+	nextInstanceID  atomic.Uint64
 
 	dash *dashapi.Dashboard
 
@@ -171,6 +172,7 @@ func RunManager(cfg *mgrconfig.Config) {
 		cfg:                cfg,
 		vmPool:             vmPool,
 		corpus:             corpus.NewMonitoredCorpus(context.Background(), corpusUpdates),
+		corpusPreloaded:    make(chan bool),
 		target:             cfg.Target,
 		sysTarget:          cfg.SysTarget,
 		reporter:           reporter,
@@ -190,7 +192,7 @@ func RunManager(cfg *mgrconfig.Config) {
 		saturatedCalls:     make(map[string]bool),
 	}
 
-	mgr.preloadCorpus()
+	go mgr.preloadCorpus()
 	mgr.initStats() // Initializes prometheus variables.
 	mgr.initHTTP()  // Creates HTTP server.
 	mgr.collectUsedFiles()
@@ -587,7 +589,6 @@ func (pool *ResourcePool) TakeOne() *int {
 }
 
 func (mgr *Manager) preloadCorpus() {
-	log.Logf(0, "loading corpus...")
 	corpusDB, err := db.Open(filepath.Join(mgr.cfg.Workdir, "corpus.db"), true)
 	if err != nil {
 		if corpusDB == nil {
@@ -610,9 +611,11 @@ func (mgr *Manager) preloadCorpus() {
 			mgr.seeds = append(mgr.seeds, data)
 		}
 	}
+	close(mgr.corpusPreloaded)
 }
 
 func (mgr *Manager) loadCorpus() {
+	<-mgr.corpusPreloaded
 	// By default we don't re-minimize/re-smash programs from corpus,
 	// it takes lots of time on start and is unnecessary.
 	// However, on version bumps we can selectively re-minimize/re-smash.