Re: [PATCH v1 6/9] mm: memcg: put memcg1-specific struct mem_cgroup's members under CONFIG_MEMCG_V1

Shakeel Butt
2024-06-29T00:49:04Z

On Fri, Jun 28, 2024 at 09:03:14PM GMT, Roman Gushchin wrote:
> Put memcg1-specific members of struct mem_cgroup under the
> CONFIG_MEMCG_V1 config option. Also group them close to the end
> of struct mem_cgroup just before the dynamic per-node part.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
> ---
> include/linux/memcontrol.h | 103 +++++++++++++++++++------------------
> 1 file changed, 53 insertions(+), 50 deletions(-)
>
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 44ab6394c9ed..107b0c5d6eab 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -188,10 +188,6 @@ struct mem_cgroup {
> struct page_counter memsw; /* v1 only */
> };
>
> - /* Legacy consumer-oriented counters */
> - struct page_counter kmem; /* v1 only */
> - struct page_counter tcpmem; /* v1 only */
> -
> /* Range enforcement for interrupt charges */
> struct work_struct high_work;
>
> @@ -205,8 +201,6 @@ struct mem_cgroup {
> bool zswap_writeback;
> #endif
>
> - unsigned long soft_limit;
> -
> /* vmpressure notifications */
> struct vmpressure vmpressure;
>
> @@ -215,13 +209,7 @@ struct mem_cgroup {
> */
> bool oom_group;
>
> - /* protected by memcg_oom_lock */
> - bool oom_lock;
> - int under_oom;
> -
> - int swappiness;
> - /* OOM-Killer disable */
> - int oom_kill_disable;
> + int swappiness;
>
> /* memory.events and memory.events.local */
> struct cgroup_file events_file;
> @@ -230,27 +218,6 @@ struct mem_cgroup {
> /* handle for "memory.swap.events" */
> struct cgroup_file swap_events_file;
>
> - /* protect arrays of thresholds */
> - struct mutex thresholds_lock;
> -
> - /* thresholds for memory usage. RCU-protected */
> - struct mem_cgroup_thresholds thresholds;
> -
> - /* thresholds for mem+swap usage. RCU-protected */
> - struct mem_cgroup_thresholds memsw_thresholds;
> -
> - /* For oom notifier event fd */
> - struct list_head oom_notify;
> -
> - /*
> - * Should we move charges of a task when a task is moved into this
> - * mem_cgroup ? And what type of charges should we move ?
> - */
> - unsigned long move_charge_at_immigrate;
> - /* taken only while moving_account > 0 */
> - spinlock_t move_lock;
> - unsigned long move_lock_flags;
> -
> CACHELINE_PADDING(_pad1_);

Let's also remove these _pad1_ and also _pad2_ as well as this
rearrangement nullifies the reasons behind these paddings. We need to
run some perf benchmarks to identify the newer false cache sharing
ields.