Bug #110490 add a option to get the malloc lib infomation of MySQL server use

• Submitted: 24 Mar 2023 11:08
• Modified: 24 Mar 2023 11:51
• Reporter: bin wang (OCA)
• Status: Verified
• Category: MySQL Server: Options
• Severity: S3 (Non-critical)
• Version: Ver 8.0
• OS: Any
• CPU Architecture: Any
• Tags: Contribution

[24 Mar 2023 11:08] bin wang

Description:
when configure  MySQL with tcmalloc or jemalloc lib, it is  hard to confirm whether it is effective or not, has no option to see the malloc infomation,
Add a malloc option will be more convenient  for checking malloc configurition.

How to repeat:
export LD_PRELOAD=/root/libjemalloc.so
./mysqld --defaults-file=my.cnf &
mysql -uroot
show variables like "%malloc%";
Empty set (0.01 sec)

Suggested fix:
export LD_PRELOAD=/root/libjemalloc.so 
show variables like "%malloc%";
+------------------------+------------------------------------------------------------+
| Variable_name          | Value                                                      |
+------------------------+------------------------------------------------------
export LD_PRELOAD=/root/libjemalloc.so 
show variables like "%malloc%";
------+
| malloc_library | jemalloc 5.3.0-0-g54eaed1d8b56b1aa528be3bdd1877e59c56fa90c |
+------------------------+------------------------------------------------------------+
1 row in set (0.01 sec)

mysql> show variables like "%malloc%";
+------------------------+--------------------------+
| Variable_name          | Value                    |
+------------------------+--------------------------+
| malloc_library | tcmalloc gperftools 2.10 |
+------------------------+--------------------------+
1 row in set (0.01 sec)

[24 Mar 2023 11:09] bin wang

suggested add  patch

(*) I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it.

Contribution: malloc.patch (application/octet-stream, text), 2.07 KiB.

[24 Mar 2023 11:14] bin wang

export LD_PRELOAD=/root/libjemalloc.so 
mysql> show variables like "%malloc%";
+------------------------+------------------------------------------------------------+
| Variable_name          | Value                                                      |
+------------------------+------------------------------------------------------------+
| malloc_library | jemalloc 5.3.0-0-g54eaed1d8b56b1aa528be3bdd1877e59c56fa90c |
+------------------------+------------------------------------------------------------+
1 row in set (0.00 sec)

export LD_PRELOAD=/root/libtcmalloc.so 
mysql> show variables like "%malloc%";
+------------------------+--------------------------+
| Variable_name          | Value                    |
+------------------------+--------------------------+
| malloc_library | tcmalloc gperftools 2.10 |
+------------------------+--------------------------+
1 row in set (0.00 sec)

[24 Mar 2023 11:51] MySQL Verification Team

Hello bin wang,

Thank you for the report and contribution.

regards,
Umesh