On 9/26/22 21:59, Shakeel Butt wrote:
> This reverts commit 1d0403d20f6c281cb3d14c5f1db5317caeec48e9.
>
> Anatoly Pugachev reported that the commit 1d0403d20f6c ("net: set proper
> memcg for net_init hooks allocations") is somehow causing the sparc64
> VMs failed to boot and the VMs boot fine with that patch reverted. So,
> revert the patch for now and later we can debug the issue.
>
Link: https://lore.kernel.org/all/20220918092849.GA10314@xxxxxxxxxxxx/
(mainly for regzbot reading this thread but should be valid usage for
the report anyway)
Fixes: 1d0403d20f6c ("net: set proper memcg for net_init hooks allocations")
> Reported-by: Anatoly Pugachev <matorola@xxxxxxxxx>
> Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
> Cc: Vasily Averin <vvs@xxxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: Michal Koutný <mkoutny@xxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Cc: cgroups@xxxxxxxxxxxxxxx
> Cc: sparclinux@xxxxxxxxxxxxxxx
> Cc: linux-mm@xxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
> include/linux/memcontrol.h | 45 --------------------------------------
> net/core/net_namespace.c | 7 ------
> 2 files changed, 52 deletions(-)
>
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index ef479e554253..e1644a24009c 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -1787,42 +1787,6 @@ static inline void count_objcg_event(struct obj_cgroup *objcg,
> rcu_read_unlock();
> }
>
> -/**
> - * get_mem_cgroup_from_obj - get a memcg associated with passed kernel object.
> - * @p: pointer to object from which memcg should be extracted. It can be NULL.
> - *
> - * Retrieves the memory group into which the memory of the pointed kernel
> - * object is accounted. If memcg is found, its reference is taken.
> - * If a passed kernel object is uncharged, or if proper memcg cannot be found,
> - * as well as if mem_cgroup is disabled, NULL is returned.
> - *
> - * Return: valid memcg pointer with taken reference or NULL.
> - */
> -static inline struct mem_cgroup *get_mem_cgroup_from_obj(void *p)
> -{
> - struct mem_cgroup *memcg;
> -
> - rcu_read_lock();
> - do {
> - memcg = mem_cgroup_from_obj(p);
> - } while (memcg && !css_tryget(&memcg->css));
> - rcu_read_unlock();
> - return memcg;
> -}
> -
> -/**
> - * mem_cgroup_or_root - always returns a pointer to a valid memory cgroup.
> - * @memcg: pointer to a valid memory cgroup or NULL.
> - *
> - * If passed argument is not NULL, returns it without any additional checks
> - * and changes. Otherwise, root_mem_cgroup is returned.
> - *
> - * NOTE: root_mem_cgroup can be NULL during early boot.
> - */
> -static inline struct mem_cgroup *mem_cgroup_or_root(struct mem_cgroup *memcg)
> -{
> - return memcg ? memcg : root_mem_cgroup;
> -}
> #else
> static inline bool mem_cgroup_kmem_disabled(void)
> {
> @@ -1879,15 +1843,6 @@ static inline void count_objcg_event(struct obj_cgroup *objcg,
> {
> }
>
> -static inline struct mem_cgroup *get_mem_cgroup_from_obj(void *p)
> -{
> - return NULL;
> -}
> -
> -static inline struct mem_cgroup *mem_cgroup_or_root(struct mem_cgroup *memcg)
> -{
> - return NULL;
> -}
> #endif /* CONFIG_MEMCG_KMEM */
>
> #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP)
> diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
> index 6b9f19122ec1..0ec2f5906a27 100644
> --- a/net/core/net_namespace.c
> +++ b/net/core/net_namespace.c
> @@ -18,7 +18,6 @@
> #include <linux/user_namespace.h>
> #include <linux/net_namespace.h>
> #include <linux/sched/task.h>
> -#include <linux/sched/mm.h>
> #include <linux/uidgid.h>
> #include <linux/cookie.h>
>
> @@ -1144,13 +1143,7 @@ static int __register_pernet_operations(struct list_head *list,
> * setup_net() and cleanup_net() are not possible.
> */
> for_each_net(net) {
> - struct mem_cgroup *old, *memcg;
> -
> - memcg = mem_cgroup_or_root(get_mem_cgroup_from_obj(net));
> - old = set_active_memcg(memcg);
> error = ops_init(ops, net);
> - set_active_memcg(old);
> - mem_cgroup_put(memcg);
> if (error)
> goto out_undo;
> list_add_tail(&net->exit_list, &net_exit_list);
