From: Muchun Song <songmuchun@xxxxxxxxxxxxx> Subject: mm: memcontrol: remove the kmem states Now the kmem states is only used to indicate whether the kmem is offline. However, we can set ->kmemcg_id to -1 to indicate whether the kmem is offline. Finally, we can remove the kmem states to simplify the code. Link: https://lkml.kernel.org/r/20211025125259.56624-1-songmuchun@xxxxxxxxxxxxx Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Acked-by: Roman Gushchin <guro@xxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/memcontrol.h | 7 ------- mm/memcontrol.c | 7 ++----- 2 files changed, 2 insertions(+), 12 deletions(-) --- a/include/linux/memcontrol.h~mm-memcontrol-remove-the-kmem-states +++ a/include/linux/memcontrol.h @@ -180,12 +180,6 @@ struct mem_cgroup_thresholds { struct mem_cgroup_threshold_ary *spare; }; -enum memcg_kmem_state { - KMEM_NONE, - KMEM_ALLOCATED, - KMEM_ONLINE, -}; - #if defined(CONFIG_SMP) struct memcg_padding { char x[0]; @@ -318,7 +312,6 @@ struct mem_cgroup { #ifdef CONFIG_MEMCG_KMEM int kmemcg_id; - enum memcg_kmem_state kmem_state; struct obj_cgroup __rcu *objcg; struct list_head objcg_list; /* list of inherited objcgs */ #endif --- a/mm/memcontrol.c~mm-memcontrol-remove-the-kmem-states +++ a/mm/memcontrol.c @@ -3626,7 +3626,6 @@ static int memcg_online_kmem(struct mem_ return 0; BUG_ON(memcg->kmemcg_id >= 0); - BUG_ON(memcg->kmem_state); memcg_id = memcg_alloc_cache_id(); if (memcg_id < 0) @@ -3643,7 +3642,6 @@ static int memcg_online_kmem(struct mem_ static_branch_enable(&memcg_kmem_enabled_key); memcg->kmemcg_id = memcg_id; - memcg->kmem_state = KMEM_ONLINE; return 0; } @@ -3653,11 +3651,9 @@ static void memcg_offline_kmem(struct me struct mem_cgroup *parent; int kmemcg_id; - if (memcg->kmem_state != KMEM_ONLINE) + if (memcg->kmemcg_id == -1) return; - memcg->kmem_state = KMEM_ALLOCATED; - parent = parent_mem_cgroup(memcg); if (!parent) parent = root_mem_cgroup; @@ -3676,6 +3672,7 @@ static void memcg_offline_kmem(struct me memcg_drain_all_list_lrus(kmemcg_id, parent); memcg_free_cache_id(kmemcg_id); + memcg->kmemcg_id = -1; } #else static int memcg_online_kmem(struct mem_cgroup *memcg) _