Re: message queue limits

[Andrew Morton <akpm@osdl.org>]

Marcelo Tosatti <marcelo.tosatti@cyclades.com> wrote:
>
> This should be working, but for some reason rlim[RLIMIT_MSGQUEUE].rlim_cur of
> all tasks is 0, remembering it sets init_tasks's value at ipc/mqueue.c's __init function:
> 
> 	init_task.rlim[RLIMIT_MSGQUEUE].rlim_cur = 64;
> 	init_task.rlim[RLIMIT_MSGQUEUE].rlim_max = 64;

init_task is the task_struct for process 0, "swapper".  But by the time we
run the initcalls, process 1 ("init") is up and running.

So by the time you execute these assignments, you're changing the limits on
a process which will never again create any children.

It's a bit hacky, but you could do

	BUG_ON(current->pid != 1);
	current->rlim[RLIMIT_MSGQUEUE].rlim_cur = 64;

but longer-term these initialisations should be moved into
include/asm-foo/reousrce.h:INIT_RLIMITS