memcg: remove memcg_kmem_skip_account

The flag memcg_kmem_skip_account was added during the era of opt-out kmem
accounting.  There is no need for such flag in the opt-in world as there
aren't any __GFP_ACCOUNT allocations within memcg_create_cache_enqueue().

Link: http://lkml.kernel.org/r/20180919004501.178023-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 1 insertions, 26 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index b8fcc6b3080c..8f8a5418b627 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -724,9 +724,6 @@ struct task_struct {
 #endif
 #ifdef CONFIG_MEMCG
         unsigned                        in_user_fault:1;
-#ifdef CONFIG_MEMCG_KMEM
-        unsigned                        memcg_kmem_skip_account:1;
-#endif
 #endif
 #ifdef CONFIG_COMPAT_BRK
         unsigned                        brk_randomized:1;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0e9ede617b89..645ede7ad1b2 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2460,7 +2460,7 @@ static void memcg_kmem_cache_create_func(struct work_struct *w)
 /*
  * Enqueue the creation of a per-memcg kmem_cache.
  */
-static void __memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
+static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
                                                struct kmem_cache *cachep)
 {
         struct memcg_kmem_cache_create_work *cw;
@@ -2478,25 +2478,6 @@ static void __memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
         queue_work(memcg_kmem_cache_wq, &cw->work);
 }
 
-static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
-                                             struct kmem_cache *cachep)
-{
-        /*
-         * We need to stop accounting when we kmalloc, because if the
-         * corresponding kmalloc cache is not yet created, the first allocation
-         * in __memcg_schedule_kmem_cache_create will recurse.
-         *
-         * However, it is better to enclose the whole function. Depending on
-         * the debugging options enabled, INIT_WORK(), for instance, can
-         * trigger an allocation. This too, will make us recurse. Because at
-         * this point we can't allow ourselves back into memcg_kmem_get_cache,
-         * the safest choice is to do it like this, wrapping the whole function.
-         */
-        current->memcg_kmem_skip_account = 1;
-        __memcg_schedule_kmem_cache_create(memcg, cachep);
-        current->memcg_kmem_skip_account = 0;
-}
-
 static inline bool memcg_kmem_bypass(void)
 {
         if (in_interrupt() || !current->mm || (current->flags & PF_KTHREAD))
@@ -2531,9 +2512,6 @@ struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep)
         if (memcg_kmem_bypass())
                 return cachep;
 
-        if (current->memcg_kmem_skip_account)
-                return cachep;
-
         memcg = get_mem_cgroup_from_current();
         kmemcg_id = READ_ONCE(memcg->kmemcg_id);
         if (kmemcg_id < 0)