[Devel] [PATCH -mm 00/12] kmemcg reparenting

[Vladimir Davydov]

Hi Johannes, Michal

Could you please take a look at this set when you have time?

Thank you.

On 02/26/2014 07:05 PM, Vladimir Davydov wrote:
> Hi,
>
> During my recent attempt to push kmemcg shrinkers, I was pointed out
> that current kmemcg implementation has a serious design flaw - it lacks
> reparenting. Currently each memcg cache holds a css ref to its memcg and
> does not let it go until the cache is emptied. Although this approach is
> simple, it leads to memcgs hanging around for quite a long time after
> the death, which is ugly. Building something on top of that is
> unacceptable. So this patch set targets on implementing reparenting for
> kmemcg charges.
>
> [ for more details see the discussion thread:
>   https://lkml.org/lkml/2014/2/11/623 ]
>
> It is based on top of 3.14.0-rc4-mmotm and organized as follows:
>  - Patches 1-3 fix some nasty races in kmemcg implementation. I could
>    not let them live any longer, because they touch the code I'm going
>    to modify.
>  - Patches 4-6 prepare memcg_cache_params for reparenting.
>  - Patch 7 rework slab charging making it easier to track and therefore
>    reparent kmem charges, and patches 8-10 kill the old charging code.
>  - Patch 11 introduces kmemcg reparenting.
>  - Patch 12 is for slub. It fixes sysfs naming clashes that can arise
>    due to reparented caches.
>
> Please note that this patch set does not resolve all kmemcg-related
> issues - there are still plenty of them (e.g. "dangling" caches), but it
> is already big enough so I guess I'll address them later when this one
> is committed (if it will be committed at all, of course).
>
> Many thanks to Johannes Weiner, who proposed the idea and kindly
> outlined basic design principles.
>
> Thanks,
>
> Vladimir Davydov (12):
>   memcg: flush cache creation works before memcg cache destruction
>   memcg: fix race in memcg cache destruction path
>   memcg: fix root vs memcg cache destruction race
>   memcg: move slab caches list/mutex init to memcg creation
>   memcg: add pointer from memcg_cache_params to cache
>   memcg: keep all children of each root cache on a list
>   memcg: rework slab charging
>   memcg: do not charge kmalloc_large allocations
>   fork: do not charge thread_info to kmemcg
>   memcg: kill GFP_KMEMCG and stuff
>   memcg: reparent slab on css offline
>   slub: make sure all memcg caches have unique names on sysfs
>
>  include/linux/gfp.h             |    5 -
>  include/linux/memcontrol.h      |  133 ++-------
>  include/linux/slab.h            |   15 +-
>  include/linux/thread_info.h     |    2 -
>  include/trace/events/gfpflags.h |    1 -
>  kernel/fork.c                   |    4 +-
>  mm/memcontrol.c                 |  587 +++++++++++++++++----------------------
>  mm/page_alloc.c                 |   35 ---
>  mm/slab.c                       |   47 ++--
>  mm/slab.h                       |   17 +-
>  mm/slab_common.c                |  100 +++++--
>  mm/slub.c                       |   88 ++++--
>  12 files changed, 470 insertions(+), 564 deletions(-)
>