tikv: commit all keys asynchronously in async commit (#19936)

Signed-off-by: youjiali1995 <zlwgx1023@gmail.com>

store/tikv/2pc.go

@@ -482,8 +482,9 @@ func (c *twoPhaseCommitter) doActionOnGroupMutations(bo *Backoffer, action twoPh
 		}
 	})
 
-	if firstIsPrimary && (actionIsCommit || actionIsCleanup || actionIsPessimiticLock) {
-		// primary should be committed/cleanup/pessimistically locked first
+	if firstIsPrimary &&
+		((actionIsCommit && !c.isAsyncCommit()) || actionIsCleanup || actionIsPessimiticLock) {
+		// primary should be committed(not async commit)/cleanup/pessimistically locked first
 		err = c.doActionOnBatches(bo, action, batchBuilder.primaryBatch())
 		if err != nil {
 			return errors.Trace(err)
@@ -494,7 +495,8 @@ func (c *twoPhaseCommitter) doActionOnGroupMutations(bo *Backoffer, action twoPh
 		}
 		batchBuilder.forgetPrimary()
 	}
-	if actionIsCommit && !actionCommit.retry {
+	// Already spawned a goroutine for async commit transaction.
+	if actionIsCommit && !actionCommit.retry && !c.isAsyncCommit() {
 		secondaryBo := NewBackofferWithVars(context.Background(), int(atomic.LoadUint64(&CommitMaxBackoff)), c.txn.vars)
 		go func() {
 			e := c.doActionOnBatches(secondaryBo, action, batchBuilder.allBatches())