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 v5 2/7] mm: memcontrol: introduce obj_cgroup_{un}charge_pages
Date: Sat, 20 Mar 2021 00:38:15 +0800 [thread overview]
Message-ID: <20210319163821.20704-3-songmuchun@bytedance.com> (raw)
In-Reply-To: <20210319163821.20704-1-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 | 63 ++++++++++++++++++++++++++++++++++++---------------------
1 file changed, 40 insertions(+), 23 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2cda76ff0629..9489c7fc1e04 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2905,6 +2905,20 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg)
page->memcg_data = (unsigned long)memcg;
}
+static struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg)
+{
+ struct mem_cgroup *memcg;
+
+ rcu_read_lock();
+retry:
+ memcg = obj_cgroup_memcg(objcg);
+ if (unlikely(!css_tryget(&memcg->css)))
+ goto retry;
+ rcu_read_unlock();
+
+ return memcg;
+}
+
#ifdef CONFIG_MEMCG_KMEM
int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
gfp_t gfp, bool new_page)
@@ -3056,6 +3070,29 @@ static void memcg_free_cache_id(int id)
ida_simple_remove(&memcg_cache_ida, id);
}
+static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg,
+ unsigned int nr_pages)
+{
+ struct mem_cgroup *memcg;
+
+ memcg = get_mem_cgroup_from_objcg(objcg);
+ __memcg_kmem_uncharge(memcg, nr_pages);
+ css_put(&memcg->css);
+}
+
+static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp,
+ unsigned int nr_pages)
+{
+ struct mem_cgroup *memcg;
+ int ret;
+
+ memcg = get_mem_cgroup_from_objcg(objcg);
+ 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
@@ -3180,19 +3217,8 @@ 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) {
- struct mem_cgroup *memcg;
-
- rcu_read_lock();
-retry:
- memcg = obj_cgroup_memcg(old);
- if (unlikely(!css_tryget(&memcg->css)))
- goto retry;
- rcu_read_unlock();
-
- __memcg_kmem_uncharge(memcg, nr_pages);
- css_put(&memcg->css);
- }
+ if (nr_pages)
+ obj_cgroup_uncharge_pages(old, nr_pages);
/*
* The leftover is flushed to the centralized per-memcg value.
@@ -3250,7 +3276,6 @@ 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;
@@ -3267,24 +3292,16 @@ 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:[~2021-03-19 16:39 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 16:38 [PATCH v5 0/7] Use obj_cgroup APIs to charge kmem pages Muchun Song
2021-03-19 16:38 ` [PATCH v5 1/7] mm: memcontrol: slab: fix obtain a reference to a freeing memcg Muchun Song
2021-03-19 18:26 ` Shakeel Butt
2021-03-22 14:46 ` Johannes Weiner
2021-03-23 9:18 ` [External] " Muchun Song
2021-03-22 18:17 ` Roman Gushchin
2021-03-19 16:38 ` Muchun Song [this message]
2021-03-19 16:38 ` [PATCH v5 3/7] mm: memcontrol: directly access page->memcg_data in mm/page_alloc.c Muchun Song
2021-03-19 16:38 ` [PATCH v5 4/7] mm: memcontrol: change ug->dummy_page only if memcg changed Muchun Song
2021-03-19 16:38 ` [PATCH v5 5/7] mm: memcontrol: use obj_cgroup APIs to charge kmem pages Muchun Song
2021-03-19 18:27 ` Shakeel Butt
2021-03-22 18:13 ` Roman Gushchin
2021-03-19 16:38 ` [PATCH v5 6/7] mm: memcontrol: inline __memcg_kmem_{un}charge() into obj_cgroup_{un}charge_pages() Muchun Song
2021-03-19 18:41 ` Shakeel Butt
2021-03-22 14:34 ` Johannes Weiner
2021-03-22 18:14 ` Roman Gushchin
2021-03-19 16:38 ` [PATCH v5 7/7] mm: memcontrol: move PageMemcgKmem to the scope of CONFIG_MEMCG_KMEM Muchun Song
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210319163821.20704-3-songmuchun@bytedance.com \
--to=songmuchun@bytedance.com \
--cc=akpm@linux-foundation.org \
--cc=duanxiongchun@bytedance.com \
--cc=guro@fb.com \
--cc=hannes@cmpxchg.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=shakeelb@google.com \
--cc=vdavydov.dev@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).