Re: mlock() issues

[Masao Uebayashi <uebayasi%tombi.co.jp@localhost>]

On Wed, Oct 20, 2010 at 06:29:53PM +0100, Sad Clouds wrote:
> Hi, I've been trying to figure out why it's not possible to lock more
> than 666MB of memory, and I'm beginning to think it might be a kernel
> issue.
> 
> This is what I'm doing:
> 
> Run program as root.
> Lock only memory segments that are multiples of system page size.
> ulimit -l is set to unlimited.
> proc.curproc.rlimit.memorylocked.soft = 697976149
> proc.curproc.rlimit.memorylocked.hard = 2093928448
> 
> With all of the above set, for some reason it's not possible to lock
> more than 666MB.
> 
> Can anyone shed some light on this?

IIRCC:

- Those two (soft/hard) numbers are calculated at process 0
  initialization.

- setrlimit(2) doesn't seem to handle RLIMIT_MEMLOCK.

- mlock(2)/mlockall(2) refer to the "soft" counterpart.

What if you change "proc.curproc.rlimit.memorylocked.soft" sysctl
value from within the program?