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authorRoman Gushchin <guro@fb.com>2019-07-12 06:56:09 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-12 21:05:44 +0300
commit434866947564b954409c2fe561605e22f7b49f64 (patch)
tree7ee227d29c0d5db895af0a1e953aa8959a41a5f2
parent0b14e8aa68223c2c124d408aa4b110b364d13c53 (diff)
downloadlinux-434866947564b954409c2fe561605e22f7b49f64.tar.xz
mm: memcg/slab: generalize postponed non-root kmem_cache deactivation
Currently SLUB uses a work scheduled after an RCU grace period to deactivate a non-root kmem_cache. This mechanism can be reused for kmem_caches release, but requires generalization for SLAB case. Introduce kmemcg_cache_deactivate() function, which calls allocator-specific __kmem_cache_deactivate() and schedules execution of __kmem_cache_deactivate_after_rcu() with all necessary locks in a worker context after an rcu grace period. Here is the new calling scheme: kmemcg_cache_deactivate() __kmemcg_cache_deactivate() SLAB/SLUB-specific kmemcg_rcufn() rcu kmemcg_workfn() work __kmemcg_cache_deactivate_after_rcu() SLAB/SLUB-specific instead of: __kmemcg_cache_deactivate() SLAB/SLUB-specific slab_deactivate_memcg_cache_rcu_sched() SLUB-only kmemcg_rcufn() rcu kmemcg_workfn() work kmemcg_cache_deact_after_rcu() SLUB-only For consistency, all allocator-specific functions start with "__". Link: http://lkml.kernel.org/r/20190611231813.3148843-4-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Waiman Long <longman@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/slab.c4
-rw-r--r--mm/slab.h3
-rw-r--r--mm/slab_common.c27
-rw-r--r--mm/slub.c8
4 files changed, 14 insertions, 28 deletions
diff --git a/mm/slab.c b/mm/slab.c
index badd98f7e2f1..30347bd3f19c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2252,6 +2252,10 @@ void __kmemcg_cache_deactivate(struct kmem_cache *cachep)
{
__kmem_cache_shrink(cachep);
}
+
+void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s)
+{
+}
#endif
int __kmem_cache_shutdown(struct kmem_cache *cachep)
diff --git a/mm/slab.h b/mm/slab.h
index 7ef695b91919..dc83583ee9dd 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -172,6 +172,7 @@ int __kmem_cache_shutdown(struct kmem_cache *);
void __kmem_cache_release(struct kmem_cache *);
int __kmem_cache_shrink(struct kmem_cache *);
void __kmemcg_cache_deactivate(struct kmem_cache *s);
+void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s);
void slab_kmem_cache_release(struct kmem_cache *);
struct seq_file;
@@ -290,8 +291,6 @@ static __always_inline void memcg_uncharge_slab(struct page *page, int order,
extern void slab_init_memcg_params(struct kmem_cache *);
extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg);
-extern void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s,
- void (*work_fn)(struct kmem_cache *));
#else /* CONFIG_MEMCG_KMEM */
diff --git a/mm/slab_common.c b/mm/slab_common.c
index f4dd9f75751c..62733bbcc971 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -708,7 +708,7 @@ static void kmemcg_workfn(struct work_struct *work)
put_online_mems();
put_online_cpus();
- /* done, put the ref from slab_deactivate_memcg_cache_rcu_sched() */
+ /* done, put the ref from kmemcg_cache_deactivate() */
css_put(&s->memcg_params.memcg->css);
}
@@ -726,31 +726,21 @@ static void kmemcg_rcufn(struct rcu_head *head)
queue_work(memcg_kmem_cache_wq, &s->memcg_params.work);
}
-/**
- * slab_deactivate_memcg_cache_rcu_sched - schedule deactivation after a
- * sched RCU grace period
- * @s: target kmem_cache
- * @work_fn: deactivation function to call
- *
- * Schedule @work_fn to be invoked with online cpus, mems and slab_mutex
- * held after a sched RCU grace period. The slab is guaranteed to stay
- * alive until @work_fn is finished. This is to be used from
- * __kmemcg_cache_deactivate().
- */
-void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s,
- void (*work_fn)(struct kmem_cache *))
+static void kmemcg_cache_deactivate(struct kmem_cache *s)
{
if (WARN_ON_ONCE(is_root_cache(s)) ||
WARN_ON_ONCE(s->memcg_params.work_fn))
return;
+ __kmemcg_cache_deactivate(s);
+
if (s->memcg_params.root_cache->memcg_params.dying)
return;
/* pin memcg so that @s doesn't get destroyed in the middle */
css_get(&s->memcg_params.memcg->css);
- s->memcg_params.work_fn = work_fn;
+ s->memcg_params.work_fn = __kmemcg_cache_deactivate_after_rcu;
call_rcu(&s->memcg_params.rcu_head, kmemcg_rcufn);
}
@@ -773,7 +763,7 @@ void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg)
if (!c)
continue;
- __kmemcg_cache_deactivate(c);
+ kmemcg_cache_deactivate(c);
arr->entries[idx] = NULL;
}
mutex_unlock(&slab_mutex);
@@ -866,11 +856,10 @@ static void flush_memcg_workqueue(struct kmem_cache *s)
mutex_unlock(&slab_mutex);
/*
- * SLUB deactivates the kmem_caches through call_rcu. Make
+ * SLAB and SLUB deactivate the kmem_caches through call_rcu. Make
* sure all registered rcu callbacks have been invoked.
*/
- if (IS_ENABLED(CONFIG_SLUB))
- rcu_barrier();
+ rcu_barrier();
/*
* SLAB and SLUB create memcg kmem_caches through workqueue and SLUB
diff --git a/mm/slub.c b/mm/slub.c
index e1402ed19e74..845aeaa6c2d4 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4008,7 +4008,7 @@ int __kmem_cache_shrink(struct kmem_cache *s)
}
#ifdef CONFIG_MEMCG
-static void kmemcg_cache_deact_after_rcu(struct kmem_cache *s)
+void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s)
{
/*
* Called with all the locks held after a sched RCU grace period.
@@ -4034,12 +4034,6 @@ void __kmemcg_cache_deactivate(struct kmem_cache *s)
*/
slub_set_cpu_partial(s, 0);
s->min_partial = 0;
-
- /*
- * s->cpu_partial is checked locklessly (see put_cpu_partial), so
- * we have to make sure the change is visible before shrinking.
- */
- slab_deactivate_memcg_cache_rcu_sched(s, kmemcg_cache_deact_after_rcu);
}
#endif /* CONFIG_MEMCG */