On Wed, Dec 22, 2021 at 5:53 AM Shakeel Butt <shakeelb@xxxxxxxxxx> wrote:
>
> The kvmalloc* allocation functions can fallback to vmalloc allocations
> and more often on long running machines. In addition the kernel does
> have __GFP_ACCOUNT kvmalloc* calls. So, often on long running machines,
> the memory.stat does not tell the complete picture which type of memory
> is charged to the memcg. So add a per-memcg vmalloc stat.
>
> Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
> ---
> Documentation/admin-guide/cgroup-v2.rst | 3 +++
> include/linux/memcontrol.h | 15 +++++++++++++++
> mm/memcontrol.c | 1 +
> mm/vmalloc.c | 5 +++++
> 4 files changed, 24 insertions(+)
>
> diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
> index 82c8dc91b2be..5aa368d165da 100644
> --- a/Documentation/admin-guide/cgroup-v2.rst
> +++ b/Documentation/admin-guide/cgroup-v2.rst
> @@ -1314,6 +1314,9 @@ PAGE_SIZE multiple when read back.
> sock (npn)
> Amount of memory used in network transmission buffers
>
> + vmalloc (npn)
> + Amount of memory used for vmap backed memory.
> +
> shmem
> Amount of cached filesystem data that is swap-backed,
> such as tmpfs, shm segments, shared anonymous mmap()s
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index d76dad703580..000bfad6ff69 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -33,6 +33,7 @@ enum memcg_stat_item {
> MEMCG_SWAP = NR_VM_NODE_STAT_ITEMS,
> MEMCG_SOCK,
> MEMCG_PERCPU_B,
> + MEMCG_VMALLOC,
> MEMCG_NR_STAT,
> };
>
> @@ -944,6 +945,15 @@ static inline void mod_memcg_state(struct mem_cgroup *memcg,
> local_irq_restore(flags);
> }
>
> +static inline void mod_memcg_page_state(struct page *page,
> + int idx, int val)
> +{
> + struct mem_cgroup *memcg = page_memcg(page);
> +
> + if (!mem_cgroup_disabled() && memcg)
> + mod_memcg_state(memcg, idx, val);
It's not safe to access @memcg throughout mod_memcg_state() for the
kmem charged through objcg infrastructure. It's supposed to be safe
to access @memcg under rcu read lock. Otherwise, it looks good to
me.
Thanks.
