[#MDEV-25250] performance schema shows negative amount of memory allocated for global_system

This test was on Windows, I did not try elsewhere.
After normal startup "mysqld --performance_schema=1", and login, negative amount of memory is allocated by global_system_variables

mysql> select * from performance_schema.memory_summary_by_thread_by_event_name where count_free > count_alloc\G

*************************** 1. row ***************************

                   THREAD_ID: 1

                  EVENT_NAME: memory/sql/global_system_variables

                 COUNT_ALLOC: 0

                  COUNT_FREE: 2

   SUM_NUMBER_OF_BYTES_ALLOC: 0

    SUM_NUMBER_OF_BYTES_FREE: 128

              LOW_COUNT_USED: -2

          CURRENT_COUNT_USED: -2

             HIGH_COUNT_USED: 0

    LOW_NUMBER_OF_BYTES_USED: -128

CURRENT_NUMBER_OF_BYTES_USED: -128

   HIGH_NUMBER_OF_BYTES_USED: 0

1 row in set (0.01 sec)

+-----------+----------------------------+--------------------+-------------------+-------------------+-------------------+-----------------+

| thread_id | user                       | current_count_used | current_allocated | current_avg_alloc | current_max_alloc | total_allocated |

+-----------+----------------------------+--------------------+-------------------+-------------------+-------------------+-----------------+

|         2 | mysys/statement_timer      |                  0 |                 0 |            0.0000 |                 0 |               0 |

|         6 | innodb/thread_pool_thread  |                  0 |                 0 |            0.0000 |                 0 |               0 |

|        10 | sql/manager                |                  0 |                 0 |            0.0000 |                 0 |               0 |

|        18 | root@localhost             |                  0 |                 0 |            0.0000 |                 0 |               0 |

|         5 | innodb/thread_pool_thread  |                  0 |                 0 |            0.0000 |                 0 |               0 |

|         9 | innodb/thread_pool_thread  |                  0 |                 0 |            0.0000 |                 0 |               0 |

|        17 | root@localhost             |                  0 |                 0 |            0.0000 |                 0 |               0 |

|         4 | innodb/page_cleaner_thread |                  0 |                 0 |            0.0000 |                 0 |               0 |

|         8 | innodb/thread_pool_thread  |                  0 |                 0 |            0.0000 |                 0 |               0 |

|        16 | root@localhost             |                  0 |                 0 |            0.0000 |                 0 |               0 |

|         3 | aria/checkpoint_background |                  0 |                 0 |            0.0000 |                 0 |               0 |

|         7 | innodb/thread_pool_thread  |                  0 |                 0 |            0.0000 |                 0 |               0 |

|        15 | root@localhost             |                  0 |                 0 |            0.0000 |                 0 |               0 |

|        19 | root@localhost             |                  0 |                 0 |            0.0000 |                 0 |               0 |

|         1 | sql/main                   |                 -2 |              -128 |           64.0000 |                 0 |               0 |

+-----------+----------------------------+--------------------+-------------------+-------------------+-------------------+-----------------+

[MDEV-25250] performance schema shows negative amount of memory allocated for global_system_variables Created: 2021-03-25 Updated: 2021-03-25 Resolved: 2021-03-25
Status:	Closed
Project:	MariaDB Server
Component/s:	Performance Schema
Affects Version/s:	None
Fix Version/s:	N/A

[MDEV-25250] performance schema shows negative amount of memory allocated for global_system_variables Created: 2021-03-25 Updated: 2021-03-25 Resolved: 2021-03-25