Re: [PATCH v5 13/14] protect architectures where THREAD_SIZE >=PAGE_SIZE against fork bombs

From: Andrew Morton
Date: Wed Oct 17 2012 - 18:12:37 EST


On Tue, 16 Oct 2012 14:16:50 +0400
Glauber Costa <glommer@xxxxxxxxxxxxx> wrote:

> @@ -146,7 +146,7 @@ void __weak arch_release_thread_info(struct thread_info *ti)
> static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
> int node)
> {
> - struct page *page = alloc_pages_node(node, THREADINFO_GFP,
> + struct page *page = alloc_pages_node(node, THREADINFO_GFP_ACCOUNTED,
> THREAD_SIZE_ORDER);

yay, we actually used all this code for something ;)

I don't think we really saw a comprehensive list of what else the kmem
controller will be used for, but I believe that all other envisaged
applications will require slab accounting, yes?


So it appears that all we have at present is a
yet-another-fork-bomb-preventer, but one which requires that the
culprit be in a container? That's reasonable, given your
hosted-environment scenario. It's unclear (to me) that we should merge
all this code for only this feature. Again, it would be good to have a
clear listing of and plan for other applications of this code.
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