return NOTIFY_OK;
}
-/**
- * mem_cgroup_try_charge - try charging a memcg
- * @memcg: memcg to charge
- * @nr_pages: number of pages to charge
- *
- * Returns 0 if @memcg was charged successfully, -EINTR if the charge
- * was bypassed to root_mem_cgroup, and -ENOMEM if the charge failed.
- */
-static int mem_cgroup_try_charge(struct mem_cgroup *memcg,
- gfp_t gfp_mask,
- unsigned int nr_pages)
+static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
+ unsigned int nr_pages)
{
unsigned int batch = max(CHARGE_BATCH, nr_pages);
int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
return ret;
}
-/**
- * mem_cgroup_try_charge_mm - try charging a mm
- * @mm: mm_struct to charge
- * @nr_pages: number of pages to charge
- * @oom: trigger OOM if reclaim fails
- *
- * Returns the charged mem_cgroup associated with the given mm_struct or
- * NULL the charge failed.
- */
-static struct mem_cgroup *mem_cgroup_try_charge_mm(struct mm_struct *mm,
- gfp_t gfp_mask,
- unsigned int nr_pages)
-
-{
- struct mem_cgroup *memcg;
- int ret;
-
- memcg = get_mem_cgroup_from_mm(mm);
- ret = mem_cgroup_try_charge(memcg, gfp_mask, nr_pages);
- css_put(&memcg->css);
- if (ret == -EINTR)
- memcg = root_mem_cgroup;
- else if (ret)
- memcg = NULL;
-
- return memcg;
-}
-
-/*
- * Somemtimes we have to undo a charge we got by try_charge().
- * This function is for that and do uncharge, put css's refcnt.
- * gotten by try_charge().
- */
-static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg,
- unsigned int nr_pages)
+static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
{
unsigned long bytes = nr_pages * PAGE_SIZE;
return memcg;
}
-static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
- struct page *page,
- unsigned int nr_pages,
- enum charge_type ctype,
- bool lrucare)
+static void commit_charge(struct page *page, struct mem_cgroup *memcg,
+ unsigned int nr_pages, bool anon, bool lrucare)
{
struct page_cgroup *pc = lookup_page_cgroup(page);
struct zone *uninitialized_var(zone);
struct lruvec *lruvec;
bool was_on_lru = false;
- bool anon;
lock_page_cgroup(pc);
VM_BUG_ON_PAGE(PageCgroupUsed(pc), page);
spin_unlock_irq(&zone->lru_lock);
}
- if (ctype == MEM_CGROUP_CHARGE_TYPE_ANON)
- anon = true;
- else
- anon = false;
-
mem_cgroup_charge_statistics(memcg, page, anon, nr_pages);
unlock_page_cgroup(pc);
if (ret)
return ret;
- ret = mem_cgroup_try_charge(memcg, gfp, size >> PAGE_SHIFT);
+ ret = try_charge(memcg, gfp, size >> PAGE_SHIFT);
if (ret == -EINTR) {
/*
- * mem_cgroup_try_charge() chosed to bypass to root due to
- * OOM kill or fatal signal. Since our only options are to
- * either fail the allocation or charge it to this cgroup, do
- * it as a temporary condition. But we can't fail. From a
- * kmem/slab perspective, the cache has already been selected,
- * by mem_cgroup_kmem_get_cache(), so it is too late to change
+ * try_charge() chose to bypass to root due to OOM kill or
+ * fatal signal. Since our only options are to either fail
+ * the allocation or charge it to this cgroup, do it as a
+ * temporary condition. But we can't fail. From a kmem/slab
+ * perspective, the cache has already been selected, by
+ * mem_cgroup_kmem_get_cache(), so it is too late to change
* our minds.
*
* This condition will only trigger if the task entered
- * memcg_charge_kmem in a sane state, but was OOM-killed during
- * mem_cgroup_try_charge() above. Tasks that were already
- * dying when the allocation triggers should have been already
+ * memcg_charge_kmem in a sane state, but was OOM-killed
+ * during try_charge() above. Tasks that were already dying
+ * when the allocation triggers should have been already
* directed to the root cgroup in memcontrol.h
*/
res_counter_charge_nofail(&memcg->res, size, &fail_res);
return ret;
}
-int mem_cgroup_charge_anon(struct page *page,
- struct mm_struct *mm, gfp_t gfp_mask)
-{
- unsigned int nr_pages = 1;
- struct mem_cgroup *memcg;
-
- if (mem_cgroup_disabled())
- return 0;
-
- VM_BUG_ON_PAGE(page_mapped(page), page);
- VM_BUG_ON_PAGE(page->mapping && !PageAnon(page), page);
- VM_BUG_ON(!mm);
-
- if (PageTransHuge(page)) {
- nr_pages <<= compound_order(page);
- VM_BUG_ON_PAGE(!PageTransHuge(page), page);
- }
-
- memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, nr_pages);
- if (!memcg)
- return -ENOMEM;
- __mem_cgroup_commit_charge(memcg, page, nr_pages,
- MEM_CGROUP_CHARGE_TYPE_ANON, false);
- return 0;
-}
-
-/*
- * While swap-in, try_charge -> commit or cancel, the page is locked.
- * And when try_charge() successfully returns, one refcnt to memcg without
- * struct page_cgroup is acquired. This refcnt will be consumed by
- * "commit()" or removed by "cancel()"
- */
-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 = NULL;
- struct page_cgroup *pc;
- int ret;
-
- pc = lookup_page_cgroup(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 (PageCgroupUsed(pc))
- goto out;
- if (do_swap_account)
- memcg = try_get_mem_cgroup_from_page(page);
- if (!memcg)
- memcg = get_mem_cgroup_from_mm(mm);
- ret = mem_cgroup_try_charge(memcg, mask, 1);
- css_put(&memcg->css);
- if (ret == -EINTR)
- memcg = root_mem_cgroup;
- else if (ret)
- return ret;
-out:
- *memcgp = memcg;
- return 0;
-}
-
-int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page,
- gfp_t gfp_mask, struct mem_cgroup **memcgp)
-{
- if (mem_cgroup_disabled()) {
- *memcgp = NULL;
- 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)) {
- struct mem_cgroup *memcg;
-
- memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, 1);
- if (!memcg)
- return -ENOMEM;
- *memcgp = memcg;
- return 0;
- }
- 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())
- return;
- if (!memcg)
- return;
- __mem_cgroup_cancel_charge(memcg, 1);
-}
-
-static void
-__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
- enum charge_type ctype)
-{
- if (mem_cgroup_disabled())
- return;
- if (!memcg)
- return;
-
- __mem_cgroup_commit_charge(memcg, page, 1, ctype, true);
- /*
- * Now swap is on-memory. This means this page may be
- * counted both as mem and swap....double count.
- * Fix it by uncharging from memsw. Basically, this SwapCache is stable
- * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
- * may call delete_from_swap_cache() before reach here.
- */
- if (do_swap_account && PageSwapCache(page)) {
- swp_entry_t ent = {.val = page_private(page)};
- mem_cgroup_uncharge_swap(ent);
- }
-}
-
-void mem_cgroup_commit_charge_swapin(struct page *page,
- struct mem_cgroup *memcg)
-{
- __mem_cgroup_commit_charge_swapin(page, memcg,
- MEM_CGROUP_CHARGE_TYPE_ANON);
-}
-
-int mem_cgroup_charge_file(struct page *page, struct mm_struct *mm,
- gfp_t gfp_mask)
-{
- enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
- struct mem_cgroup *memcg;
- int ret;
-
- if (mem_cgroup_disabled())
- return 0;
- if (PageCompound(page))
- return 0;
-
- if (PageSwapCache(page)) { /* shmem */
- ret = __mem_cgroup_try_charge_swapin(mm, page,
- gfp_mask, &memcg);
- if (ret)
- return ret;
- __mem_cgroup_commit_charge_swapin(page, memcg, type);
- return 0;
- }
-
- memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, 1);
- if (!memcg)
- return -ENOMEM;
- __mem_cgroup_commit_charge(memcg, page, 1, type, false);
- return 0;
-}
-
static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg,
unsigned int nr_pages,
const enum charge_type ctype)
struct mem_cgroup *memcg = NULL;
unsigned int nr_pages = 1;
struct page_cgroup *pc;
- enum charge_type ctype;
*memcgp = NULL;
* page. In the case new page is migrated but not remapped, new page's
* mapcount will be finally 0 and we call uncharge in end_migration().
*/
- if (PageAnon(page))
- ctype = MEM_CGROUP_CHARGE_TYPE_ANON;
- else
- 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
* old one and only one page is going to be left afterwards.
*/
- __mem_cgroup_commit_charge(memcg, newpage, nr_pages, ctype, false);
+ commit_charge(newpage, memcg, nr_pages, PageAnon(page), false);
}
/* remove redundant charge if migration failed*/
{
struct mem_cgroup *memcg = NULL;
struct page_cgroup *pc;
- enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
if (mem_cgroup_disabled())
return;
* the newpage may be on LRU(or pagevec for LRU) already. We lock
* LRU while we overwrite pc->mem_cgroup.
*/
- __mem_cgroup_commit_charge(memcg, newpage, 1, type, true);
+ commit_charge(newpage, memcg, 1, false, true);
}
#ifdef CONFIG_DEBUG_VM
int ret;
/* Try a single bulk charge without reclaim first */
- ret = mem_cgroup_try_charge(mc.to, GFP_KERNEL & ~__GFP_WAIT, count);
+ ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_WAIT, count);
if (!ret) {
mc.precharge += count;
return ret;
}
if (ret == -EINTR) {
- __mem_cgroup_cancel_charge(root_mem_cgroup, count);
+ cancel_charge(root_mem_cgroup, count);
return ret;
}
/* Try charges one by one with reclaim */
while (count--) {
- ret = mem_cgroup_try_charge(mc.to,
- GFP_KERNEL & ~__GFP_NORETRY, 1);
+ ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_NORETRY, 1);
/*
* In case of failure, any residual charges against
* mc.to will be dropped by mem_cgroup_clear_mc()
* bypassed to root right away or they'll be lost.
*/
if (ret == -EINTR)
- __mem_cgroup_cancel_charge(root_mem_cgroup, 1);
+ cancel_charge(root_mem_cgroup, 1);
if (ret)
return ret;
mc.precharge++;
/* we must uncharge all the leftover precharges from mc.to */
if (mc.precharge) {
- __mem_cgroup_cancel_charge(mc.to, mc.precharge);
+ cancel_charge(mc.to, mc.precharge);
mc.precharge = 0;
}
/*
* we must uncharge here.
*/
if (mc.moved_charge) {
- __mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
+ cancel_charge(mc.from, mc.moved_charge);
mc.moved_charge = 0;
}
/* we must fixup refcnts and charges */
}
#endif
+/**
+ * mem_cgroup_try_charge - try charging a page
+ * @page: page to charge
+ * @mm: mm context of the victim
+ * @gfp_mask: reclaim mode
+ * @memcgp: charged memcg return
+ *
+ * Try to charge @page to the memcg that @mm belongs to, reclaiming
+ * pages according to @gfp_mask if necessary.
+ *
+ * Returns 0 on success, with *@memcgp pointing to the charged memcg.
+ * Otherwise, an error code is returned.
+ *
+ * After page->mapping has been set up, the caller must finalize the
+ * charge with mem_cgroup_commit_charge(). Or abort the transaction
+ * with mem_cgroup_cancel_charge() in case page instantiation fails.
+ */
+int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
+ gfp_t gfp_mask, struct mem_cgroup **memcgp)
+{
+ struct mem_cgroup *memcg = NULL;
+ unsigned int nr_pages = 1;
+ int ret = 0;
+
+ if (mem_cgroup_disabled())
+ goto out;
+
+ if (PageSwapCache(page)) {
+ struct page_cgroup *pc = lookup_page_cgroup(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 (PageCgroupUsed(pc))
+ goto out;
+ }
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ 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);
+
+ ret = try_charge(memcg, gfp_mask, nr_pages);
+
+ css_put(&memcg->css);
+
+ if (ret == -EINTR) {
+ memcg = root_mem_cgroup;
+ ret = 0;
+ }
+out:
+ *memcgp = memcg;
+ return ret;
+}
+
+/**
+ * mem_cgroup_commit_charge - commit a page charge
+ * @page: page to charge
+ * @memcg: memcg to charge the page to
+ * @lrucare: page might be on LRU already
+ *
+ * Finalize a charge transaction started by mem_cgroup_try_charge(),
+ * after page->mapping has been set up. This must happen atomically
+ * as part of the page instantiation, i.e. under the page table lock
+ * for anonymous pages, under the page lock for page and swap cache.
+ *
+ * In addition, the page must not be on the LRU during the commit, to
+ * prevent racing with task migration. If it might be, use @lrucare.
+ *
+ * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
+ */
+void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
+ bool lrucare)
+{
+ unsigned int nr_pages = 1;
+
+ VM_BUG_ON_PAGE(!page->mapping, page);
+ VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page);
+
+ if (mem_cgroup_disabled())
+ return;
+ /*
+ * Swap faults will attempt to charge the same page multiple
+ * times. But reuse_swap_page() might have removed the page
+ * from swapcache already, so we can't check PageSwapCache().
+ */
+ if (!memcg)
+ return;
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ VM_BUG_ON_PAGE(!PageTransHuge(page), page);
+ }
+
+ commit_charge(page, memcg, nr_pages, PageAnon(page), lrucare);
+
+ if (do_swap_account && PageSwapCache(page)) {
+ swp_entry_t entry = { .val = page_private(page) };
+ /*
+ * The swap entry might not get freed for a long time,
+ * let's not wait for it. The page already received a
+ * memory+swap charge, drop the swap entry duplicate.
+ */
+ mem_cgroup_uncharge_swap(entry);
+ }
+}
+
+/**
+ * mem_cgroup_cancel_charge - cancel a page charge
+ * @page: page to charge
+ * @memcg: memcg to charge the page to
+ *
+ * Cancel a charge transaction started by mem_cgroup_try_charge().
+ */
+void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg)
+{
+ unsigned int nr_pages = 1;
+
+ if (mem_cgroup_disabled())
+ return;
+ /*
+ * Swap faults will attempt to charge the same page multiple
+ * times. But reuse_swap_page() might have removed the page
+ * from swapcache already, so we can't check PageSwapCache().
+ */
+ if (!memcg)
+ return;
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ VM_BUG_ON_PAGE(!PageTransHuge(page), page);
+ }
+
+ cancel_charge(memcg, nr_pages);
+}
+
/*
* subsys_initcall() for memory controller.
*
projects / cascardo / linux.git / blobdiff