mq_overview(7) contains outdated, inaccurate fs.mqueue.queues_max limit description
The manpages 3.40-0.1ubuntu3 package in Ubuntu 12.10 contains an mq_overview(7) man page with outdated, severely inaccurate information regarding the /proc/sys/
"The default value for queues_max is 256; it can be changed to any value in the range 0 to INT_MAX."
This used to be true in Linux 3.2.x, as shipped in Ubuntu 12.04. However, it is no longer true with Linux 3.5.x, as shipped in 12.10.
For some inexplicable reason, upstream lowered the hard upper limit for POSIX message queues (fs.mqueue.
# sysctl -w fs.mqueue.
sysctl: setting key "fs.mqueue.
You can verify the new, post-3.5 limit at:
Please amend the man page so that the new limit is correctly documented. The undocumented change from INT_MAX queues to a mere 1024 queues is rather harsh, and it took quite some investigation to pin this down as an upstream kernel change.
|Michael Kerrisk (mtk-manpages) wrote : Re: [Bug 1155695] Re: mq_overview(7) contains outdated, inaccurate fs.mqueue.queues_max limit description||#7|