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author | Vladimir Davydov <vdavydov@parallels.com> | 2015-09-09 15:35:35 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-10 13:29:01 -0700 |
commit | e993d905c81e2c0f669f2f8e8327df86738baebe (patch) | |
tree | f37d6e76025164efc2944e7afe9d54e66a38cbc3 /mm/memcontrol.c | |
parent | 94a59fb36ee91b3f977a9b914ec701efe40041de (diff) | |
download | op-kernel-dev-e993d905c81e2c0f669f2f8e8327df86738baebe.zip op-kernel-dev-e993d905c81e2c0f669f2f8e8327df86738baebe.tar.gz |
memcg: zap try_get_mem_cgroup_from_page
It is only used in mem_cgroup_try_charge, so fold it in and zap it.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memcontrol.c')
-rw-r--r-- | mm/memcontrol.c | 48 |
1 files changed, 12 insertions, 36 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 0100972..6ddaeba 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2099,40 +2099,6 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) css_put_many(&memcg->css, nr_pages); } -/* - * try_get_mem_cgroup_from_page - look up page's memcg association - * @page: the page - * - * Look up, get a css reference, and return the memcg that owns @page. - * - * The page must be locked to prevent racing with swap-in and page - * cache charges. If coming from an unlocked page table, the caller - * must ensure the page is on the LRU or this can race with charging. - */ -struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) -{ - struct mem_cgroup *memcg; - unsigned short id; - swp_entry_t ent; - - VM_BUG_ON_PAGE(!PageLocked(page), page); - - memcg = page->mem_cgroup; - if (memcg) { - if (!css_tryget_online(&memcg->css)) - memcg = NULL; - } else if (PageSwapCache(page)) { - ent.val = page_private(page); - id = lookup_swap_cgroup_id(ent); - rcu_read_lock(); - memcg = mem_cgroup_from_id(id); - if (memcg && !css_tryget_online(&memcg->css)) - memcg = NULL; - rcu_read_unlock(); - } - return memcg; -} - static void lock_page_lru(struct page *page, int *isolated) { struct zone *zone = page_zone(page); @@ -5329,8 +5295,20 @@ int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, * the page lock, which serializes swap cache removal, which * in turn serializes uncharging. */ + VM_BUG_ON_PAGE(!PageLocked(page), page); if (page->mem_cgroup) goto out; + + if (do_swap_account) { + swp_entry_t ent = { .val = page_private(page), }; + unsigned short id = lookup_swap_cgroup_id(ent); + + rcu_read_lock(); + memcg = mem_cgroup_from_id(id); + if (memcg && !css_tryget_online(&memcg->css)) + memcg = NULL; + rcu_read_unlock(); + } } if (PageTransHuge(page)) { @@ -5338,8 +5316,6 @@ int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, VM_BUG_ON_PAGE(!PageTransHuge(page), page); } - if (do_swap_account && PageSwapCache(page)) - memcg = try_get_mem_cgroup_from_page(page); if (!memcg) memcg = get_mem_cgroup_from_mm(mm); |