So that the hwpoison injector can get mem_cgroup for arbitrary page and thus know whether it is owned by some mem_cgroup task(s). CC: KOSAKI Motohiro CC: Hugh Dickins CC: Daisuke Nishimura CC: Balbir Singh Acked-by: KAMEZAWA Hiroyuki Signed-off-by: Wu Fengguang --- include/linux/memcontrol.h | 6 ++++++ mm/memcontrol.c | 11 ++++------- 2 files changed, 10 insertions(+), 7 deletions(-) --- linux-mm.orig/mm/memcontrol.c 2009-11-02 10:18:42.000000000 +0800 +++ linux-mm/mm/memcontrol.c 2009-11-02 10:26:21.000000000 +0800 @@ -1379,25 +1379,22 @@ static struct mem_cgroup *mem_cgroup_loo return container_of(css, struct mem_cgroup, css); } -static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page) +struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) { - struct mem_cgroup *mem; + struct mem_cgroup *mem = NULL; struct page_cgroup *pc; unsigned short id; swp_entry_t ent; VM_BUG_ON(!PageLocked(page)); - if (!PageSwapCache(page)) - return NULL; - pc = lookup_page_cgroup(page); lock_page_cgroup(pc); if (PageCgroupUsed(pc)) { mem = pc->mem_cgroup; if (mem && !css_tryget(&mem->css)) mem = NULL; - } else { + } else if (PageSwapCache(page)) { ent.val = page_private(page); id = lookup_swap_cgroup(ent); rcu_read_lock(); @@ -1742,7 +1739,7 @@ int mem_cgroup_try_charge_swapin(struct */ if (!PageSwapCache(page)) return 0; - mem = try_get_mem_cgroup_from_swapcache(page); + mem = try_get_mem_cgroup_from_page(page); if (!mem) goto charge_cur_mm; *ptr = mem; --- linux-mm.orig/include/linux/memcontrol.h 2009-11-02 10:18:42.000000000 +0800 +++ linux-mm/include/linux/memcontrol.h 2009-11-02 10:26:21.000000000 +0800 @@ -68,6 +68,7 @@ extern unsigned long mem_cgroup_isolate_ extern void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask); int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem); +extern struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page); extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p); static inline @@ -189,6 +190,11 @@ mem_cgroup_move_lists(struct page *page, { } +static inline struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) +{ + return NULL; +} + static inline int mm_match_cgroup(struct mm_struct *mm, struct mem_cgroup *mem) { return 1; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/