Bug #50531 LockPagesInMainMemory documentation note not correct

• Submitted: 22 Jan 2010 7:39
• Modified: 22 Jan 2010 18:02
• Reporter: Andrew Hutchings
• Status: Closed
• Category: MySQL Server: Documentation
• Severity: S3 (Non-critical)
• OS: Any
• Assigned to: Jon Stephens
• CPU Architecture: Any

[22 Jan 2010 7:39] Andrew Hutchings

Description:
In http://dev.mysql.com/doc/refman/5.1/en/mysql-cluster-ndbd-definition.html :

LockPagesInMainMemory
...
"Note

To make use of this parameter, the data node process must be run as system root."

This is not correct.  LockPagesInMainMemory uses the mlockall function and unprivileged users can lock pages if the OS is configured to do so.

From Linux kernel 2.6.9 unprivileged users can lock memory limited by "max locked memory" in the OS limits (see ulimit -l and http://linux.die.net/man/2/mlock)

I believe Solaris 10 requires PRIV_PROC_LOCK_MEMORY in privileges, I'm not sure about other limits:
http://docs.sun.com/app/docs/doc/816-5168/mlockall-3c?l=en&a=view

How to repeat:
.

[22 Jan 2010 14:47] Jon Stephens

Meant for me.

[22 Jan 2010 18:02] Jon Stephens

Thank you for your bug report. This issue has been addressed in the documentation. The updated documentation will appear on our website shortly, and will be included in the next release of the relevant products.