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| author | Johannes Weiner <jweiner@redhat.com> | 2012-01-12 17:18:43 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-12 20:13:06 -0800 |
| commit | 7a0524cfc8f9f585471a31b1282a9ce4a1a7d444 (patch) | |
| tree | 4e31e1ec7e892d67e48d1199b9e8590ad5718e7a /mm/memcontrol.c | |
| parent | 00c54c0bac24bb02d2460c516da76651a7451286 (diff) | |
| download | lwn-7a0524cfc8f9f585471a31b1282a9ce4a1a7d444.tar.gz lwn-7a0524cfc8f9f585471a31b1282a9ce4a1a7d444.zip | |
mm: memcg: remove unneeded checks from newpage_charge()
All callsites pass in freshly allocated pages and a valid mm. As a
result, all checks pertaining to the page's mapcount, page->mapping or the
fallback to init_mm are unneeded.
Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
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 | 16 |
1 files changed, 4 insertions, 12 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index a63ad141083c..2450d89486d4 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2748,19 +2748,11 @@ int mem_cgroup_newpage_charge(struct page *page, { if (mem_cgroup_disabled()) return 0; - /* - * If already mapped, we don't have to account. - * If page cache, page->mapping has address_space. - * But page->mapping may have out-of-use anon_vma pointer, - * detecit it by PageAnon() check. newly-mapped-anon's page->mapping - * is NULL. - */ - if (page_mapped(page) || (page->mapping && !PageAnon(page))) - return 0; - if (unlikely(!mm)) - mm = &init_mm; + VM_BUG_ON(page_mapped(page)); + VM_BUG_ON(page->mapping && !PageAnon(page)); + VM_BUG_ON(!mm); return mem_cgroup_charge_common(page, mm, gfp_mask, - MEM_CGROUP_CHARGE_TYPE_MAPPED); + MEM_CGROUP_CHARGE_TYPE_MAPPED); } static void |