*: track the memory usage of runtime info

executor/adapter.go

@@ -741,6 +741,7 @@ func (a *ExecStmt) handleNoDelay(ctx context.Context, e Executor, isPessimistic
 		// `rs.Close` in `handleStmt`
 		if handled && sc != nil && rs == nil {
 			sc.DetachMemDiskTracker()
+			sc.ClearRuntimeInfo()
 		}
 	}()
 
@@ -1415,6 +1416,7 @@ func (a *ExecStmt) CloseRecordSet(txnStartTS uint64, lastErr error) {
 	a.FinishExecuteStmt(txnStartTS, lastErr, false)
 	a.logAudit()
 	a.Ctx.GetSessionVars().StmtCtx.DetachMemDiskTracker()
+	a.Ctx.GetSessionVars().StmtCtx.ClearRuntimeInfo()
 }
 
 // LogSlowQuery is used to print the slow query in the log files.

executor/builder.go

@@ -4498,6 +4498,7 @@ func (builder *dataReaderBuilder) buildTableReaderBase(ctx context.Context, e *T
 		SetClosestReplicaReadAdjuster(newClosestReadAdjuster(e.ctx, &reqBuilderWithRange.Request, e.netDataSize)).
 		SetPaging(e.paging).
 		SetConnID(e.ctx.GetSessionVars().ConnectionID).
+		SetMemTracker(e.memTracker).
 		Build()
 	if err != nil {
 		return nil, err

executor/distsql.go

@@ -803,6 +803,7 @@ func (e *IndexLookUpExecutor) buildTableReader(ctx context.Context, task *lookup
 		plans:            e.tblPlans,
 		netDataSize:      e.avgRowSize * float64(len(task.handles)),
 		byItems:          e.byItems,
+		memTracker:       e.memTracker,
 	}
 	tableReaderExec.buildVirtualColumnInfo()
 	tableReader, err := e.dataReaderBuilder.buildTableReaderFromHandles(ctx, tableReaderExec, task.handles, true)

server/conn.go

@@ -2108,6 +2108,7 @@ func (cc *clientConn) handleStmt(ctx context.Context, stmt ast.StmtNode, warns [
 		// will not be detached. We need to detach them manually.
 		if sv := cc.ctx.GetSessionVars(); sv != nil && sv.StmtCtx != nil {
 			sv.StmtCtx.DetachMemDiskTracker()
+			sv.StmtCtx.ClearRuntimeInfo()
 		}
 		return true, err
 	}

sessionctx/stmtctx/stmtctx.go

@@ -1229,6 +1229,19 @@ func (sc *StatementContext) DetachMemDiskTracker() {
 	}
 }
 
+// ClearRuntimeInfo clears the runtime info.
+func (sc *StatementContext) ClearRuntimeInfo() {
+	if sc == nil {
+		return
+	}
+	sc.mu.Lock()
+	defer sc.mu.Unlock()
+	sc.mu.allExecDetails = nil
+	if sc.RuntimeStatsColl != nil {
+		sc.RuntimeStatsColl = execdetails.NewRuntimeStatsColl(sc.RuntimeStatsColl)
+	}
+}
+
 // CopTasksDetails collects some useful information of cop-tasks during execution.
 type CopTasksDetails struct {
 	NumCopTasks int

store/copr/coprocessor.go

@@ -1682,6 +1682,7 @@ func (worker *copIteratorWorker) handleCollectExecutionInfo(bo *Backoffer, rpcCt
 	if rpcCtx != nil {
 		resp.detail.CalleeAddress = rpcCtx.Addr
 	}
+	worker.memTracker.Consume(execdetails.AvgMemorySizeForDetailsNeedP90)
 	sd := &util.ScanDetail{}
 	td := util.TimeDetail{}
 	if pbDetails := resp.pbResp.ExecDetailsV2; pbDetails != nil {

util/execdetails/execdetails.go

@@ -23,6 +23,7 @@ import (
 	"sync"
 	"sync/atomic"
 	"time"
+	"unsafe"
 
 	"github.com/pingcap/tipb/go-tipb"
 	"github.com/tikv/client-go/v2/util"
@@ -50,6 +51,13 @@ type DetailsNeedP90 struct {
 	TimeDetail    util.TimeDetail
 }
 
+// AvgMemorySizeForDetailsNeedP90 is the estimated size of DetailsNeedP90 struct.
+// "48" represents the base memory overhead of a Go map after initialization.
+// Here, the memory overhead of the `BackoffSleep` and `BackoffTimes` member attributes is recorded.
+// "8" represents the memory overhead of some related slices. For details, see the following function:
+// StatementContext.MergeExecDetails(), basicCopRuntimeStats.Merge(), selectResultRuntimeStats.Merge().
+const AvgMemorySizeForDetailsNeedP90 = int64(unsafe.Sizeof(DetailsNeedP90{})) + 48*2 + 8*4
+
 type stmtExecDetailKeyType struct{}
 
 // StmtExecDetailKey used to carry StmtExecDetail info in context.Context.