Re: [PATCH] [request for inclusion] Realtime LSM

[Paul Davis <paul@linuxaudiosystems.com>]

>> rlimit_memlock limits the *amount* of memory that mlock() can be used
>> on, not whether mlock can be used. at least, thats my understanding of
>> the POSIX design for this. the man page and the source code for mlock
>> support make that reasonably clear.
>
>eh no. It defaults to zero, but if you increase it for a specific user, that
>user is allowed to mlock more.

from mm/mlock.c:do_mlock() in 2.6.8:

	if (on && !capable(CAP_IPC_LOCK))
		return -EPERM;

i.e. only root or capabilities can make mlock() usable.

>much). If you are unwilling to even discuss fixing the underlying design
>issues then I'm scared that this issue will never come to any workable
>solution.

Lee, Jack and I have been very willing to discuss the issue. Christoph
isn't willing to discuss it, he's just told us "its the wrong design,
and I'm not telling you why or what's better". If there is a better
design that will end up in the mainstream kernel, we'd love to see it
implemented, and will likely be involved in doing it, because its
really important to us.

--p