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| author | Roman Gushchin <guro@fb.com> | 2020-04-02 07:06:36 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-02 19:35:28 +0300 |
| commit | 4f103c6363c3fe88182037acf4a50f295bde19da (patch) | |
| tree | 12cbd268a00f7d7cfeb7085b6cd605d2e823b3df /mm/memcontrol.c | |
| parent | 86daf94efb11d7319fbef5e480018c4807add6ef (diff) | |
| download | linux-4f103c6363c3fe88182037acf4a50f295bde19da.tar.xz | |
mm: memcg/slab: use mem_cgroup_from_obj()
Sometimes we need to get a memcg pointer from a charged kernel object.
The right way to get it depends on whether it's a proper slab object or
it's backed by raw pages (e.g. it's a vmalloc alloction). In the first
case the kmem_cache->memcg_params.memcg indirection should be used; in
other cases it's just page->mem_cgroup.
To simplify this task and hide the implementation details let's use the
mem_cgroup_from_obj() helper, which takes a pointer to any kernel object
and returns a valid memcg pointer or NULL.
Passing a kernel address rather than a pointer to a page will allow to use
this helper for per-object (rather than per-page) tracked objects in the
future.
The caller is still responsible to ensure that the returned memcg isn't
going away underneath: take the rcu read lock, cgroup mutex etc; depending
on the context.
mem_cgroup_from_kmem() defined in mm/list_lru.c is now obsolete and can be
removed.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Link: http://lkml.kernel.org/r/20200117203609.3146239-1-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index d8334e0710a7..c1aa24a57e55 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -759,13 +759,12 @@ void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val) { - struct page *page = virt_to_head_page(p); - pg_data_t *pgdat = page_pgdat(page); + pg_data_t *pgdat = page_pgdat(virt_to_page(p)); struct mem_cgroup *memcg; struct lruvec *lruvec; rcu_read_lock(); - memcg = memcg_from_slab_page(page); + memcg = mem_cgroup_from_obj(p); /* Untracked pages have no memcg, no lruvec. Update only the node */ if (!memcg || memcg == root_mem_cgroup) { |