From: Muchun Song <songmuchun@bytedance.com>
To: guro@fb.com, hannes@cmpxchg.org, mhocko@kernel.org,
akpm@linux-foundation.org, shakeelb@google.com,
vdavydov.dev@gmail.com
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
duanxiongchun@bytedance.com,
Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH v4 1/5] mm: memcontrol: introduce obj_cgroup_{un}charge_pages
Date: Thu, 18 Mar 2021 19:06:54 +0800 [thread overview]
Message-ID: <20210318110658.60892-2-songmuchun@bytedance.com> (raw)
In-Reply-To: <20210318110658.60892-1-songmuchun@bytedance.com>
We know that the unit of slab object charging is bytes, the unit of
kmem page charging is PAGE_SIZE. If we want to reuse obj_cgroup APIs
to charge the kmem pages, we should pass PAGE_SIZE (as third parameter)
to obj_cgroup_charge(). Because the size is already PAGE_SIZE, we can
skip touch the objcg stock. And obj_cgroup_{un}charge_pages() are
introduced to charge in units of page level.
In the later patch, we also can reuse those two helpers to charge or
uncharge a number of kernel pages to a object cgroup. This is just
a code movement without any functional changes.
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
---
mm/memcontrol.c | 46 +++++++++++++++++++++++++++++++---------------
1 file changed, 31 insertions(+), 15 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 845eec01ef9d..fc22da9805fb 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3056,6 +3056,34 @@ static void memcg_free_cache_id(int id)
ida_simple_remove(&memcg_cache_ida, id);
}
+static inline void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg,
+ unsigned int nr_pages)
+{
+ rcu_read_lock();
+ __memcg_kmem_uncharge(obj_cgroup_memcg(objcg), nr_pages);
+ rcu_read_unlock();
+}
+
+static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp,
+ unsigned int nr_pages)
+{
+ struct mem_cgroup *memcg;
+ int ret;
+
+ rcu_read_lock();
+retry:
+ memcg = obj_cgroup_memcg(objcg);
+ if (unlikely(!css_tryget(&memcg->css)))
+ goto retry;
+ rcu_read_unlock();
+
+ ret = __memcg_kmem_charge(memcg, gfp, nr_pages);
+
+ css_put(&memcg->css);
+
+ return ret;
+}
+
/**
* __memcg_kmem_charge: charge a number of kernel pages to a memcg
* @memcg: memory cgroup to charge
@@ -3180,11 +3208,8 @@ static void drain_obj_stock(struct memcg_stock_pcp *stock)
unsigned int nr_pages = stock->nr_bytes >> PAGE_SHIFT;
unsigned int nr_bytes = stock->nr_bytes & (PAGE_SIZE - 1);
- if (nr_pages) {
- rcu_read_lock();
- __memcg_kmem_uncharge(obj_cgroup_memcg(old), nr_pages);
- rcu_read_unlock();
- }
+ if (nr_pages)
+ obj_cgroup_uncharge_pages(old, nr_pages);
/*
* The leftover is flushed to the centralized per-memcg value.
@@ -3242,7 +3267,6 @@ static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes)
int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size)
{
- struct mem_cgroup *memcg;
unsigned int nr_pages, nr_bytes;
int ret;
@@ -3259,24 +3283,16 @@ int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size)
* refill_obj_stock(), called from this function or
* independently later.
*/
- rcu_read_lock();
-retry:
- memcg = obj_cgroup_memcg(objcg);
- if (unlikely(!css_tryget(&memcg->css)))
- goto retry;
- rcu_read_unlock();
-
nr_pages = size >> PAGE_SHIFT;
nr_bytes = size & (PAGE_SIZE - 1);
if (nr_bytes)
nr_pages += 1;
- ret = __memcg_kmem_charge(memcg, gfp, nr_pages);
+ ret = obj_cgroup_charge_pages(objcg, gfp, nr_pages);
if (!ret && nr_bytes)
refill_obj_stock(objcg, PAGE_SIZE - nr_bytes);
- css_put(&memcg->css);
return ret;
}
--
2.11.0
next prev parent reply other threads:[~2021-03-18 11:09 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-18 11:06 [PATCH v4 0/5] Use obj_cgroup APIs to charge kmem pages Muchun Song
2021-03-18 11:06 ` Muchun Song [this message]
2021-03-18 11:06 ` [PATCH v4 2/5] mm: memcontrol: directly access page->memcg_data in mm/page_alloc.c Muchun Song
2021-03-18 15:09 ` Johannes Weiner
2021-03-19 1:00 ` Shakeel Butt
2021-03-18 11:06 ` [PATCH v4 3/5] mm: memcontrol: change ug->dummy_page only if memcg changed Muchun Song
2021-03-18 15:11 ` Johannes Weiner
2021-03-19 1:22 ` Shakeel Butt
2021-03-18 11:06 ` [PATCH v4 4/5] mm: memcontrol: use obj_cgroup APIs to charge kmem pages Muchun Song
2021-03-18 15:23 ` Johannes Weiner
2021-03-19 3:39 ` Shakeel Butt
2021-03-19 4:05 ` [External] " Muchun Song
2021-03-19 13:59 ` Shakeel Butt
2021-03-19 15:45 ` Muchun Song
2021-03-18 11:06 ` [PATCH v4 5/5] mm: memcontrol: move PageMemcgKmem to the scope of CONFIG_MEMCG_KMEM Muchun Song
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