statistics: fix LoadStatsFromJSONNoUpdate func for CPUNum = 1 (pi…

…ngcap#49375) close pingcap#49374
lance6716 · Dec 12, 2023 · 2ca7121 · 2ca7121
1 parent 4b1cccb
commit 2ca7121
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Showing 3 changed files with 13 additions and 10 deletions.
diff --git a/pkg/statistics/handle/storage/dump_test.go b/pkg/statistics/handle/storage/dump_test.go
@@ -19,6 +19,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"runtime"
 	"strings"
 	"testing"
 
@@ -226,6 +227,10 @@ func TestLoadPartitionStats(t *testing.T) {
 func TestLoadPartitionStatsErrPanic(t *testing.T) {
 	store, dom := testkit.CreateMockStoreAndDomain(t)
 	tk := testkit.NewTestKit(t, store)
+	val := runtime.GOMAXPROCS(1)
+	defer func() {
+		runtime.GOMAXPROCS(val)
+	}()
 	tk.MustExec("use test")
 	tk.MustExec("set @@tidb_analyze_version = 2")
 	tk.MustExec("set @@tidb_partition_prune_mode = 'dynamic'")

diff --git a/pkg/statistics/handle/storage/stats_read_writer.go b/pkg/statistics/handle/storage/stats_read_writer.go
@@ -558,7 +558,7 @@ type TestLoadStatsErr struct{}
 // LoadStatsFromJSON will load statistic from JSONTable, and save it to the storage.
 // In final, it will also udpate the stats cache.
 func (s *statsReadWriter) LoadStatsFromJSON(ctx context.Context, is infoschema.InfoSchema,
-	jsonTbl *util.JSONTable, concurrencyForPartition uint8) error {
+	jsonTbl *util.JSONTable, concurrencyForPartition int) error {
 	if err := s.LoadStatsFromJSONNoUpdate(ctx, is, jsonTbl, concurrencyForPartition); err != nil {
 		return errors.Trace(err)
 	}
@@ -567,14 +567,12 @@ func (s *statsReadWriter) LoadStatsFromJSON(ctx context.Context, is infoschema.I
 
 // LoadStatsFromJSONNoUpdate will load statistic from JSONTable, and save it to the storage.
 func (s *statsReadWriter) LoadStatsFromJSONNoUpdate(ctx context.Context, is infoschema.InfoSchema,
-	jsonTbl *util.JSONTable, concurrencyForPartition uint8) error {
-	nCPU := uint8(runtime.GOMAXPROCS(0))
+	jsonTbl *util.JSONTable, concurrencyForPartition int) error {
+	nCPU := runtime.GOMAXPROCS(0)
 	if concurrencyForPartition == 0 {
-		concurrencyForPartition = nCPU / 2 // default
-	}
-	if concurrencyForPartition > nCPU {
-		concurrencyForPartition = nCPU // for safety
+		concurrencyForPartition = (nCPU + 1) / 2 // default
 	}
+	concurrencyForPartition = min(concurrencyForPartition, nCPU) // for safety
 
 	table, err := is.TableByName(model.NewCIStr(jsonTbl.DatabaseName), model.NewCIStr(jsonTbl.TableName))
 	if err != nil {
@@ -596,7 +594,7 @@ func (s *statsReadWriter) LoadStatsFromJSONNoUpdate(ctx context.Context, is info
 		close(taskCh)
 		var wg sync.WaitGroup
 		e := new(atomic.Pointer[error])
-		for i := 0; i < int(concurrencyForPartition); i++ {
+		for i := 0; i < concurrencyForPartition; i++ {
 			wg.Add(1)
 			s.statsHandler.GPool().Go(func() {
 				defer func() {

diff --git a/pkg/statistics/handle/types/interfaces.go b/pkg/statistics/handle/types/interfaces.go
@@ -299,10 +299,10 @@ type StatsReadWriter interface {
 
 	// LoadStatsFromJSON will load statistic from JSONTable, and save it to the storage.
 	// In final, it will also udpate the stats cache.
-	LoadStatsFromJSON(ctx context.Context, is infoschema.InfoSchema, jsonTbl *statsutil.JSONTable, concurrencyForPartition uint8) error
+	LoadStatsFromJSON(ctx context.Context, is infoschema.InfoSchema, jsonTbl *statsutil.JSONTable, concurrencyForPartition int) error
 
 	// LoadStatsFromJSONNoUpdate will load statistic from JSONTable, and save it to the storage.
-	LoadStatsFromJSONNoUpdate(ctx context.Context, is infoschema.InfoSchema, jsonTbl *statsutil.JSONTable, concurrencyForPartition uint8) error
+	LoadStatsFromJSONNoUpdate(ctx context.Context, is infoschema.InfoSchema, jsonTbl *statsutil.JSONTable, concurrencyForPartition int) error
 
 	// Methods for extended stast.