*: enable global memory control by default

executor/executor.go

@@ -100,6 +100,8 @@ var (
 	_ Executor = &TopNExec{}
 	_ Executor = &UnionExec{}
 
+	// GlobalMemoryUsageTracker is the ancestor of all the Executors' memory tracker and GlobalMemory Tracker
+	GlobalMemoryUsageTracker *memory.Tracker
 	// GlobalDiskUsageTracker is the ancestor of all the Executors' disk tracker
 	GlobalDiskUsageTracker *disk.Tracker
 	// GlobalAnalyzeMemoryTracker is the ancestor of all the Analyze jobs' memory tracker and child of global Tracker
@@ -149,8 +151,8 @@ type globalPanicOnExceed struct {
 
 func init() {
 	action := &globalPanicOnExceed{}
-	memory.GlobalMemoryUsageTracker = memory.NewGlobalTracker(memory.LabelForGlobalMemory, -1)
-	memory.GlobalMemoryUsageTracker.SetActionOnExceed(action)
+	GlobalMemoryUsageTracker = memory.NewGlobalTracker(memory.LabelForGlobalMemory, -1)
+	GlobalMemoryUsageTracker.SetActionOnExceed(action)
 	GlobalDiskUsageTracker = disk.NewGlobalTrcaker(memory.LabelForGlobalStorage, -1)
 	GlobalDiskUsageTracker.SetActionOnExceed(action)
 	GlobalAnalyzeMemoryTracker = memory.NewTracker(memory.LabelForGlobalAnalyzeMemory, -1)

executor/executor_test.go

@@ -6226,21 +6226,3 @@ func TestSessionRootTrackerDetach(t *testing.T) {
 	require.NoError(t, err)
 	require.Nil(t, tk.Session().GetSessionVars().MemTracker.GetFallbackForTest(false))
 }
-
-func TestServerMemoryQuota(t *testing.T) {
-	config.UpdateGlobal(func(conf *config.Config) {
-		conf.Performance.ServerMemoryQuota = 123456789000
-	})
-	defer config.RestoreFunc()()
-	store := testkit.CreateMockStore(t)
-	tk := testkit.NewTestKit(t, store)
-
-	require.Equal(t, memory.GlobalMemoryUsageTracker.GetBytesLimit(), int64(123456789000))
-	tk.MustExec("set global tidb_server_memory_limit = 3 << 30")
-	require.Equal(t, memory.GlobalMemoryUsageTracker.GetBytesLimit(), int64(-1))
-	tk.MustExec("set global tidb_server_memory_limit = 0")
-	require.Equal(t, memory.GlobalMemoryUsageTracker.GetBytesLimit(), int64(123456789000))
-	require.Equal(t, tk.Session().GetSessionVars().MemTracker.GetParentForTest(), memory.GlobalMemoryUsageTracker)
-	tk.Session().Close()
-	require.Nil(t, tk.Session().GetSessionVars().MemTracker.GetParentForTest())
-}

session/bootstrap.go

@@ -641,11 +641,13 @@ const (
 	version97 = 97
 	// version98 add a column `Token_issuer` to `mysql.user`
 	version98 = 98
+	// version99 converts server-memory-quota to a sysvar
+	version99 = 99
 )
 
 // currentBootstrapVersion is defined as a variable, so we can modify its value for testing.
 // please make sure this is the largest version
-var currentBootstrapVersion int64 = version98
+var currentBootstrapVersion int64 = version99
 
 // DDL owner key's expired time is ManagerSessionTTL seconds, we should wait the time and give more time to have a chance to finish it.
 var internalSQLTimeout = owner.ManagerSessionTTL + 15
@@ -746,8 +748,10 @@ var (
 		upgradeToVer93,
 		upgradeToVer94,
 		upgradeToVer95,
+		// We will redo upgradeToVer96 in upgradeToVer99, it is skipped here.
 		upgradeToVer97,
 		upgradeToVer98,
+		upgradeToVer99,
 	}
 )
 
@@ -1978,6 +1982,14 @@ func upgradeToVer98(s Session, ver int64) {
 	doReentrantDDL(s, "ALTER TABLE mysql.user ADD COLUMN IF NOT EXISTS `Token_issuer` varchar(255)")
 }
 
+func upgradeToVer99(s Session, ver int64) {
+	if ver >= version99 {
+		return
+	}
+	valStr := strconv.Itoa(int(config.GetGlobalConfig().Performance.ServerMemoryQuota))
+	importConfigOption(s, "performance.server-memory-quota", variable.TiDBServerMemoryLimit, valStr)
+}
+
 func writeOOMAction(s Session) {
 	comment := "oom-action is `log` by default in v3.0.x, `cancel` by default in v4.0.11+"
 	mustExecute(s, `INSERT HIGH_PRIORITY INTO %n.%n VALUES (%?, %?, %?) ON DUPLICATE KEY UPDATE VARIABLE_VALUE= %?`,

session/session.go

@@ -2572,9 +2572,6 @@ func (s *session) Close() {
 	s.RollbackTxn(ctx)
 	if s.sessionVars != nil {
 		s.sessionVars.WithdrawAllPreparedStmt()
-		if s.sessionVars.MemTracker != nil {
-			s.sessionVars.MemTracker.Detach()
-		}
 	}
 	if s.stmtStats != nil {
 		s.stmtStats.SetFinished()

sessionctx/variable/session.go

@@ -1698,7 +1698,6 @@ func NewSessionVars(hctx HookContext) *SessionVars {
 	vars.DiskTracker = disk.NewTracker(memory.LabelForSession, -1)
 	vars.MemTracker = memory.NewTracker(memory.LabelForSession, vars.MemQuotaQuery)
 	vars.MemTracker.IsRootTrackerOfSess = true
-	vars.MemTracker.AttachToGlobalTracker(memory.GlobalMemoryUsageTracker)
 
 	for _, engine := range config.GetGlobalConfig().IsolationRead.Engines {
 		switch engine {

sessionctx/variable/sysvar.go

@@ -787,16 +787,6 @@ var defaultSysVars = []*SysVar{
 			memory.ServerMemoryLimitOriginText.Store(str)
 			memory.ServerMemoryLimit.Store(bt)
 			gctuner.GlobalMemoryLimitTuner.UpdateMemoryLimit()
-
-			if bt == 0 {
-				if config.GetGlobalConfig().Performance.ServerMemoryQuota < 1 {
-					memory.GlobalMemoryUsageTracker.SetBytesLimit(-1)
-				} else {
-					memory.GlobalMemoryUsageTracker.SetBytesLimit(int64(config.GetGlobalConfig().Performance.ServerMemoryQuota))
-				}
-			} else {
-				memory.GlobalMemoryUsageTracker.SetBytesLimit(-1)
-			}
 			return nil
 		},
 	},

sessionctx/variable/tidb_vars.go

@@ -1146,7 +1146,7 @@ var (
 
 	// DefTiDBServerMemoryLimit indicates the default value of TiDBServerMemoryLimit(TotalMem * 80%).
 	// It should be a const and shouldn't be modified after tidb is started.
-	DefTiDBServerMemoryLimit = "0"
+	DefTiDBServerMemoryLimit = serverMemoryLimitDefaultValue()
 	GOGCTunerThreshold       = atomic.NewFloat64(DefTiDBGOGCTunerThreshold)
 )
 

tidb-server/main.go

@@ -700,11 +700,11 @@ func setGlobalVars() {
 	executor.GlobalDiskUsageTracker.SetBytesLimit(cfg.TempStorageQuota)
 	if cfg.Performance.ServerMemoryQuota < 1 {
 		// If MaxMemory equals 0, it means unlimited
-		memory.GlobalMemoryUsageTracker.SetBytesLimit(-1)
+		executor.GlobalMemoryUsageTracker.SetBytesLimit(-1)
 	} else {
-		memory.GlobalMemoryUsageTracker.SetBytesLimit(int64(cfg.Performance.ServerMemoryQuota))
+		executor.GlobalMemoryUsageTracker.SetBytesLimit(int64(cfg.Performance.ServerMemoryQuota))
 	}
-	kvcache.GlobalLRUMemUsageTracker.AttachToGlobalTracker(memory.GlobalMemoryUsageTracker)
+	kvcache.GlobalLRUMemUsageTracker.AttachToGlobalTracker(executor.GlobalMemoryUsageTracker)
 
 	t, err := time.ParseDuration(cfg.TiKVClient.StoreLivenessTimeout)
 	if err != nil || t < 0 {

util/memory/tracker.go

@@ -41,9 +41,6 @@ var (
 	TriggerMemoryLimitGC = atomicutil.NewBool(false)
 	MemoryLimitGCLast    = atomicutil.NewTime(time.Time{})
 	MemoryLimitGCTotal   = atomicutil.NewInt64(0)
-
-	// GlobalMemoryUsageTracker is the ancestor of all the Executors' memory tracker and GlobalMemory Tracker
-	GlobalMemoryUsageTracker *Tracker
 )
 
 // Tracker is used to track the memory usage during query execution.
@@ -762,11 +759,6 @@ func (t *Tracker) setParent(parent *Tracker) {
 	t.parMu.parent = parent
 }
 
-// GetParentForTest return the parent of the Tracker. Only used by test.
-func (t *Tracker) GetParentForTest() *Tracker {
-	return t.getParent()
-}
-
 // CountAllChildrenMemUse return memory used tree for the tracker
 func (t *Tracker) CountAllChildrenMemUse() map[string]int64 {
 	trackerMemUseMap := make(map[string]int64, 1024)