[PATCH] memcg: do not expose uninitialized mem_cgroup_per_node to world

[Andrew Morton]

On Fri, 10 Jun 2011 18:57:40 +0200
Igor Mammedov <imammedo at redhat.com> wrote:

> On 06/08/2011 11:09 PM, Andrew Morton wrote:
> > The original patch:
> >
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -4707,7 +4707,6 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
> >   	if (!pn)
> >   		return 1;
> >
> > -	mem->info.nodeinfo[node] = pn;
> >   	for (zone = 0; zone<  MAX_NR_ZONES; zone++) {
> >   		mz =&pn->zoneinfo[zone];
> >   		for_each_lru(l)
> > @@ -4716,6 +4715,7 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
> >   		mz->on_tree = false;
> >   		mz->mem = mem;
> >   	}
> > +	mem->info.nodeinfo[node] = pn;
> >   	return 0;
> >   }
> >
> > looks like a really good idea.  But it needs a new changelog and I'd be
> > a bit reluctant to merge it as it appears that the aptch removes our
> > only known way of reproducing a bug.
> >
> > So for now I think I'll queue the patch up unchangelogged so the issue
> > doesn't get forgotten about.
> >
> Problem was in rhel's xen hv.
> It was missing fix for imul emulation.
> Details here 
> http://lists.xensource.com/archives/html/xen-devel/2011-06/msg00801.html
> Thanks to Tim Deegan and everyone who was involved in the discussion.

I really don't want to trawl through a lengthy xen bug report and write
your changelog for you.

We still have no changelog for this patch.  Please send one.