Re: [PATCH] mm: kmem: make mem_cgroup_from_obj() vmalloc()-safe

From: Roman Gushchin
Date: Fri Jun 10 2022 - 14:10:33 EST


On Fri, Jun 10, 2022 at 11:03:10AM -0700, Roman Gushchin wrote:
> Currently mem_cgroup_from_obj() is not working properly with objects
> allocated using vmalloc(). It creates problems in some cases, when
> it's called for static objects belonging to modules or generally
> allocated using vmalloc().
>
> This patch makes mem_cgroup_from_obj() safe to be called on objects
> allocated using vmalloc().
>
> It also introduces mem_cgroup_from_slab_obj(), which is a faster
> version to use in places when we know the object is either a slab
> object or a generic slab page (e.g. when adding an object to a lru
> list).
>
> Suggested-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> Signed-off-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
> Tested-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx>

Andrew,

this patch is supposed to fix boot issues on arm introduced by
the commit "net: set proper memcg for net_init hooks allocations".

But as no I don't see this commit in linux-next or any mm branches,
so I'm not sure if it's in stable or not. So I didn't add the Fixes
tag. If it isn't in stable yet, I'd just put the fix before the problematic
commit.

Thank you!