enum charge_type {
MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
MEM_CGROUP_CHARGE_TYPE_ANON,
- MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
NR_CHARGE_TYPE,
static void mem_cgroup_get(struct mem_cgroup *memcg);
static void mem_cgroup_put(struct mem_cgroup *memcg);
+static inline
+struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s)
+{
+ return container_of(s, struct mem_cgroup, css);
+}
+
/* Writing them here to avoid exposing memcg's inner layout */
#ifdef CONFIG_MEMCG_KMEM
#include <net/sock.h>
struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
{
- return container_of(cgroup_subsys_state(cont,
- mem_cgroup_subsys_id), struct mem_cgroup,
- css);
+ return mem_cgroup_from_css(
+ cgroup_subsys_state(cont, mem_cgroup_subsys_id));
}
struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
if (unlikely(!p))
return NULL;
- return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
- struct mem_cgroup, css);
+ return mem_cgroup_from_css(task_subsys_state(p, mem_cgroup_subsys_id));
}
struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id);
if (css) {
if (css == &root->css || css_tryget(css))
- memcg = container_of(css,
- struct mem_cgroup, css);
+ memcg = mem_cgroup_from_css(css);
} else
id = 0;
rcu_read_unlock();
* We always charge the cgroup the mm_struct belongs to.
* The mm_struct's mem_cgroup changes on task migration if the
* thread group leader migrates. It's possible that mm is not
- * set, if so charge the init_mm (happens for pagecache usage).
+ * set, if so charge the root memcg (happens for pagecache usage).
*/
if (!*ptr && !mm)
*ptr = root_mem_cgroup;
css = css_lookup(&mem_cgroup_subsys, id);
if (!css)
return NULL;
- return container_of(css, struct mem_cgroup, css);
+ return mem_cgroup_from_css(css);
}
struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
bool anon;
lock_page_cgroup(pc);
- if (unlikely(PageCgroupUsed(pc))) {
- unlock_page_cgroup(pc);
- __mem_cgroup_cancel_charge(memcg, nr_pages);
- return;
- }
+ VM_BUG_ON(PageCgroupUsed(pc));
/*
* we don't need page_cgroup_lock about tail pages, becase they are not
* accessed by any other context at this point.
* struct page_cgroup is acquired. This refcnt will be consumed by
* "commit()" or removed by "cancel()"
*/
-int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
- struct page *page,
- gfp_t mask, struct mem_cgroup **memcgp)
+static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm,
+ struct page *page,
+ gfp_t mask,
+ struct mem_cgroup **memcgp)
{
struct mem_cgroup *memcg;
+ struct page_cgroup *pc;
int ret;
- *memcgp = NULL;
-
- if (mem_cgroup_disabled())
- return 0;
-
- if (!do_swap_account)
- goto charge_cur_mm;
+ pc = lookup_page_cgroup(page);
/*
- * A racing thread's fault, or swapoff, may have already updated
- * the pte, and even removed page from swap cache: in those cases
- * do_swap_page()'s pte_same() test will fail; but there's also a
- * KSM case which does need to charge the page.
+ * Every swap fault against a single page tries to charge the
+ * page, bail as early as possible. shmem_unuse() encounters
+ * already charged pages, too. The USED bit is protected by
+ * the page lock, which serializes swap cache removal, which
+ * in turn serializes uncharging.
*/
- if (!PageSwapCache(page))
+ if (PageCgroupUsed(pc))
+ return 0;
+ if (!do_swap_account)
goto charge_cur_mm;
memcg = try_get_mem_cgroup_from_page(page);
if (!memcg)
ret = 0;
return ret;
charge_cur_mm:
- if (unlikely(!mm))
- mm = &init_mm;
ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true);
if (ret == -EINTR)
ret = 0;
return ret;
}
+int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page,
+ gfp_t gfp_mask, struct mem_cgroup **memcgp)
+{
+ *memcgp = NULL;
+ if (mem_cgroup_disabled())
+ return 0;
+ /*
+ * A racing thread's fault, or swapoff, may have already
+ * updated the pte, and even removed page from swap cache: in
+ * those cases unuse_pte()'s pte_same() test will fail; but
+ * there's also a KSM case which does need to charge the page.
+ */
+ if (!PageSwapCache(page)) {
+ int ret;
+
+ ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, memcgp, true);
+ if (ret == -EINTR)
+ ret = 0;
+ return ret;
+ }
+ return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp);
+}
+
void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
{
if (mem_cgroup_disabled())
if (PageCompound(page))
return 0;
- if (unlikely(!mm))
- mm = &init_mm;
- if (!page_is_file_cache(page))
- type = MEM_CGROUP_CHARGE_TYPE_SHMEM;
-
if (!PageSwapCache(page))
ret = mem_cgroup_charge_common(page, mm, gfp_mask, type);
else { /* page is swapcache/shmem */
- ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &memcg);
+ ret = __mem_cgroup_try_charge_swapin(mm, page,
+ gfp_mask, &memcg);
if (!ret)
__mem_cgroup_commit_charge_swapin(page, memcg, type);
}
*/
if (PageAnon(page))
ctype = MEM_CGROUP_CHARGE_TYPE_ANON;
- else if (page_is_file_cache(page))
- ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
else
- ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
+ ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
/*
* The page is committed to the memcg, but it's not actually
* charged to the res_counter since we plan on replacing the
*/
if (!memcg)
return;
-
- if (PageSwapBacked(oldpage))
- type = MEM_CGROUP_CHARGE_TYPE_SHMEM;
-
/*
* Even if newpage->mapping was NULL before starting replacement,
* the newpage may be on LRU(or pagevec for LRU) already. We lock
projects / firefly-linux-kernel-4.4.55.git / blobdiff