Re: User space out of memory approach

Marcelo Tosatti
2005-01-10T22:28:17Z

On Mon, Jan 10, 2005 at 05:43:23PM -0400, Mauricio Lin wrote:
> Hi all,
>
> We have done a comparison between the kernel version and user space
> version and apparently the behavior is similar. You can also get this
> patch and module to test it and compare with kernel OOM Killer. Here
> goes a patch and a module that moves the kernel space OOM Killer
> algorithm to user space. Let us know about your ideas.

No comments on the code itself - It is interesting to have certain pids "not selectable" by
the OOM killer. Patches which have similar funcionality have been floating around.

The userspace OOM killer is dangerous though. You have to guarantee that allocations
will NOT happen until the OOM killer is executed and the killed process is dead and
has its pages freed - allocations under OOM can cause deadlocks.

"OOM-killer-in-userspace" is unreliable, not sure if its worth the effort making
it reliable (mlock it, flagged as PF_MEMALLOC, etc).