使用top命令，看到 tidb-server的CPU占用一直保持在 430% 以上，使用 perf top 查看，前几条如下，请问这个是正常的吗？ 数据量不大，访问量也不大。TiDB版本是 4.0.3
Release Version: v4.0.3
Edition: Community
Git Commit Hash: 0529b1b493e46aae71bbe34cbe24515a2eb1b47c
Git Branch: heads/refs/tags/v4.0.3
UTC Build Time: 2020-07-24 12:06:35
GoVersion: go1.13
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false
15.67% tidb-server [.] runtime.mallocgc
9.97% tidb-server [.] runtime.mapaccess2_faststr
7.78% tidb-server [.] github.com/pingcap/tidb/privilege/privileges.(*MySQLPrivilege).RequestVerification
5.75% tidb-server [.] github.com/pingcap/tidb/util/stringutil.DoMatch
4.90% tidb-server [.] runtime.scanobject
4.18% tidb-server [.] memeqbody
3.99% tidb-server [.] strings.ToUpper
3.74% tidb-server [.] github.com/pingcap/tidb/privilege/privileges.(*baseRecord).match
3.61% tidb-server [.] runtime.heapBitsSetType
2.85% tidb-server [.] runtime.makeslice
2.77% tidb-server [.] github.com/pingcap/tidb/executor.(*hugeMemTableRetriever).setDataForColumns
2.42% tidb-server [.] github.com/pingcap/tidb/privilege/privileges.(*UserPrivileges).RequestVerification
2.10% tidb-server [.] runtime.greyobject
1.94% tidb-server [.] github.com/pingcap/tidb/privilege/privileges.(*MySQLPrivilege).matchTables
1.92% tidb-server [.] runtime.growslice
1.82% tidb-server [.] github.com/pingcap/tidb/privilege/privileges.(*MySQLPrivilege).FindAllRole
1.73% tidb-server [.] github.com/pingcap/tidb/privilege/privileges.(*MySQLPrivilege).matchDB
1.71% tidb-server [.] runtime.findObject
1.41% tidb-server [.] runtime.fastrand
1.40% tidb-server [.] github.com/pingcap/tidb/privilege/privileges.(*dbRecord).match
1.24% tidb-server [.] strings.ToLower
1.19% tidb-server [.] github.com/pingcap/tidb/privilege/privileges.(*MySQLPrivilege).matchUser
1.15% tidb-server [.] strings.EqualFold
1.05% tidb-server [.] runtime.memequal
1.03% tidb-server [.] github.com/pingcap/tidb/privilege/privileges.(*tablesPrivRecord).match
0.89% tidb-server [.] runtime.memclrNoHeapPointers
0.86% tidb-server [.] runtime.duffzero
0.76% tidb-server [.] aeshashbody
0.65% tidb-server [.] github.com/pingcap/tidb/privilege/privileges.(*MySQLPrivilege).matchColumns
