diff options
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 37 |
1 files changed, 21 insertions, 16 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index dbf571547c0..11b23f203d6 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -329,23 +329,26 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, * with it */ retry: - lock_page_cgroup(page); - pc = page_get_page_cgroup(page); - /* - * The page_cgroup exists and the page has already been accounted - */ - if (pc) { - if (unlikely(!atomic_inc_not_zero(&pc->ref_cnt))) { - /* this page is under being uncharged ? */ - unlock_page_cgroup(page); - cpu_relax(); - goto retry; - } else { - unlock_page_cgroup(page); - goto done; + if (page) { + lock_page_cgroup(page); + pc = page_get_page_cgroup(page); + /* + * The page_cgroup exists and + * the page has already been accounted. + */ + if (pc) { + if (unlikely(!atomic_inc_not_zero(&pc->ref_cnt))) { + /* this page is under being uncharged ? */ + unlock_page_cgroup(page); + cpu_relax(); + goto retry; + } else { + unlock_page_cgroup(page); + goto done; + } } + unlock_page_cgroup(page); } - unlock_page_cgroup(page); pc = kzalloc(sizeof(struct page_cgroup), gfp_mask); if (pc == NULL) @@ -404,7 +407,7 @@ retry: if (ctype == MEM_CGROUP_CHARGE_TYPE_CACHE) pc->flags |= PAGE_CGROUP_FLAG_CACHE; - if (page_cgroup_assign_new_page_cgroup(page, pc)) { + if (!page || page_cgroup_assign_new_page_cgroup(page, pc)) { /* * Another charge has been added to this page already. * We take lock_page_cgroup(page) again and read @@ -413,6 +416,8 @@ retry: res_counter_uncharge(&mem->res, PAGE_SIZE); css_put(&mem->css); kfree(pc); + if (!page) + goto done; goto retry; } |