Public bug reported: The manpages 3.40-0.1ubuntu3 package in Ubuntu 12.10 contains an mq_overview(7) man page with outdated, severely inaccurate information regarding the /proc/sys/fs/mqueue/queues_max kernel limit, as follows:
"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.queues_max) from INT_MAX to 1024 in the 3.5 kernel: # sysctl -w fs.mqueue.queues_max=1025 sysctl: setting key "fs.mqueue.queues_max": Invalid argument fs.mqueue.queues_max = 1025 You can verify the new, post-3.5 limit at: http://lxr.free-electrons.com/source/ipc/mq_sysctl.c?v=3.5#L40 http://lxr.free-electrons.com/source/include/linux/ipc_namespace.h?v=3.5#L121 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. ** Affects: manpages (Ubuntu) Importance: Undecided Status: Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1155695 Title: mq_overview(7) contains outdated, inaccurate fs.mqueue.queues_max limit description To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/manpages/+bug/1155695/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
