Merge tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core:

   - support "prefer busy polling" NAPI operation mode, where we defer
     softirq for some time expecting applications to periodically busy
     poll

   - AF_XDP: improve efficiency by more batching and hindering the
     adjacency cache prefetcher

   - af_packet: make packet_fanout.arr size configurable up to 64K

   - tcp: optimize TCP zero copy receive in presence of partial or
     unaligned reads making zero copy a performance win for much smaller
     messages

   - XDP: add bulk APIs for returning / freeing frames

   - sched: support fragmenting IP packets as they come out of conntrack

   - net: allow virtual netdevs to forward UDP L4 and fraglist GSO skbs

  BPF:

   - BPF switch from crude rlimit-based to memcg-based memory accounting

   - BPF type format information for kernel modules and related tracing
     enhancements

   - BPF implement task local storage for BPF LSM

   - allow the FENTRY/FEXIT/RAW_TP tracing programs to use
     bpf_sk_storage

  Protocols:

   - mptcp: improve multiple xmit streams support, memory accounting and
     many smaller improvements

   - TLS: support CHACHA20-POLY1305 cipher

   - seg6: add support for SRv6 End.DT4/DT6 behavior

   - sctp: Implement RFC 6951: UDP Encapsulation of SCTP

   - ppp_generic: add ability to bridge channels directly

   - bridge: Connectivity Fault Management (CFM) support as is defined
     in IEEE 802.1Q section 12.14.

  Drivers:

   - mlx5: make use of the new auxiliary bus to organize the driver
     internals

   - mlx5: more accurate port TX timestamping support

   - mlxsw:
      - improve the efficiency of offloaded next hop updates by using
        the new nexthop object API
      - support blackhole nexthops
      - support IEEE 802.1ad (Q-in-Q) bridging

   - rtw88: major bluetooth co-existance improvements

   - iwlwifi: support new 6 GHz frequency band

   - ath11k: Fast Initial Link Setup (FILS)

   - mt7915: dual band concurrent (DBDC) support

   - net: ipa: add basic support for IPA v4.5

  Refactor:

   - a few pieces of in_interrupt() cleanup work from Sebastian Andrzej
     Siewior

   - phy: add support for shared interrupts; get rid of multiple driver
     APIs and have the drivers write a full IRQ handler, slight growth
     of driver code should be compensated by the simpler API which also
     allows shared IRQs

   - add common code for handling netdev per-cpu counters

   - move TX packet re-allocation from Ethernet switch tag drivers to a
     central place

   - improve efficiency and rename nla_strlcpy

   - number of W=1 warning cleanups as we now catch those in a patchwork
     build bot

  Old code removal:

   - wan: delete the DLCI / SDLA drivers

   - wimax: move to staging

   - wifi: remove old WDS wifi bridging support"

* tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1922 commits)
  net: hns3: fix expression that is currently always true
  net: fix proc_fs init handling in af_packet and tls
  nfc: pn533: convert comma to semicolon
  af_vsock: Assign the vsock transport considering the vsock address flags
  af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path
  vsock_addr: Check for supported flag values
  vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag
  vm_sockets: Add flags field in the vsock address data structure
  net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled
  tcp: Add logic to check for SYN w/ data in tcp_simple_retransmit
  net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context
  nfc: s3fwrn5: Release the nfc firmware
  net: vxget: clean up sparse warnings
  mlxsw: spectrum_router: Use eXtended mezzanine to offload IPv4 router
  mlxsw: spectrum: Set KVH XLT cache mode for Spectrum2/3
  mlxsw: spectrum_router_xm: Introduce basic XM cache flushing
  mlxsw: reg: Add Router LPM Cache Enable Register
  mlxsw: reg: Add Router LPM Cache ML Delete Register
  mlxsw: spectrum_router_xm: Implement L-value tracking for M-index
  mlxsw: reg: Add XM Router M Table Register
  ...

7 files changed, 87 insertions, 119 deletions

diff --git a/mm/debug.c b/mm/debug.c
index ccca576b2899..8a40b3fefbeb 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -182,8 +182,8 @@ hex_only:
 		pr_warn("page dumped because: %s\n", reason);
 
 #ifdef CONFIG_MEMCG
-	if (!page_poisoned && page->mem_cgroup)
-		pr_warn("page->mem_cgroup:%px\n", page->mem_cgroup);
+	if (!page_poisoned && page->memcg_data)
+		pr_warn("pages's memcg:%lx\n", page->memcg_data);
 #endif
 }
 
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 57d08156acb1..e425bbf6711a 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -484,7 +484,7 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
 #ifdef CONFIG_MEMCG
 static inline struct deferred_split *get_deferred_split_queue(struct page *page)
 {
-	struct mem_cgroup *memcg = compound_head(page)->mem_cgroup;
+	struct mem_cgroup *memcg = page_memcg(compound_head(page));
 	struct pglist_data *pgdat = NODE_DATA(page_to_nid(page));
 
 	if (memcg)
@@ -2778,7 +2778,7 @@ void deferred_split_huge_page(struct page *page)
 {
 	struct deferred_split *ds_queue = get_deferred_split_queue(page);
 #ifdef CONFIG_MEMCG
-	struct mem_cgroup *memcg = compound_head(page)->mem_cgroup;
+	struct mem_cgroup *memcg = page_memcg(compound_head(page));
 #endif
 	unsigned long flags;
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b9419a3605eb..9c5b14fe360e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -533,7 +533,7 @@ struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page)
 {
 	struct mem_cgroup *memcg;
 
-	memcg = page->mem_cgroup;
+	memcg = page_memcg(page);
 
 	if (!memcg || !cgroup_subsys_on_dfl(memory_cgrp_subsys))
 		memcg = root_mem_cgroup;
@@ -560,16 +560,7 @@ ino_t page_cgroup_ino(struct page *page)
 	unsigned long ino = 0;
 
 	rcu_read_lock();
-	memcg = page->mem_cgroup;
-
-	/*
-	 * The lowest bit set means that memcg isn't a valid
-	 * memcg pointer, but a obj_cgroups pointer.
-	 * In this case the page is shared and doesn't belong
-	 * to any specific memory cgroup.
-	 */
-	if ((unsigned long) memcg & 0x1UL)
-		memcg = NULL;
+	memcg = page_memcg_check(page);
 
 	while (memcg && !(memcg->css.flags & CSS_ONLINE))
 		memcg = parent_mem_cgroup(memcg);
@@ -857,16 +848,17 @@ void __mod_lruvec_page_state(struct page *page, enum node_stat_item idx,
 			     int val)
 {
 	struct page *head = compound_head(page); /* rmap on tail pages */
+	struct mem_cgroup *memcg = page_memcg(head);
 	pg_data_t *pgdat = page_pgdat(page);
 	struct lruvec *lruvec;
 
 	/* Untracked pages have no memcg, no lruvec. Update only the node */
-	if (!head->mem_cgroup) {
+	if (!memcg) {
 		__mod_node_page_state(pgdat, idx, val);
 		return;
 	}
 
-	lruvec = mem_cgroup_lruvec(head->mem_cgroup, pgdat);
+	lruvec = mem_cgroup_lruvec(memcg, pgdat);
 	__mod_lruvec_state(lruvec, idx, val);
 }
 EXPORT_SYMBOL(__mod_lruvec_page_state);
@@ -1057,7 +1049,7 @@ EXPORT_SYMBOL(get_mem_cgroup_from_mm);
  */
 struct mem_cgroup *get_mem_cgroup_from_page(struct page *page)
 {
-	struct mem_cgroup *memcg = page->mem_cgroup;
+	struct mem_cgroup *memcg = page_memcg(page);
 
 	if (mem_cgroup_disabled())
 		return NULL;
@@ -1349,7 +1341,7 @@ struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct pglist_data *pgd
 		goto out;
 	}
 
-	memcg = page->mem_cgroup;
+	memcg = page_memcg(page);
 	/*
 	 * Swapcache readahead pages are added to the LRU - and
 	 * possibly migrated - before they are charged.
@@ -2114,7 +2106,7 @@ void mem_cgroup_print_oom_group(struct mem_cgroup *memcg)
 }
 
 /**
- * lock_page_memcg - lock a page->mem_cgroup binding
+ * lock_page_memcg - lock a page and memcg binding
  * @page: the page
  *
  * This function protects unlocked LRU pages from being moved to
@@ -2146,7 +2138,7 @@ struct mem_cgroup *lock_page_memcg(struct page *page)
 	if (mem_cgroup_disabled())
 		return NULL;
 again:
-	memcg = head->mem_cgroup;
+	memcg = page_memcg(head);
 	if (unlikely(!memcg))
 		return NULL;
 
@@ -2154,7 +2146,7 @@ again:
 		return memcg;
 
 	spin_lock_irqsave(&memcg->move_lock, flags);
-	if (memcg != head->mem_cgroup) {
+	if (memcg != page_memcg(head)) {
 		spin_unlock_irqrestore(&memcg->move_lock, flags);
 		goto again;
 	}
@@ -2192,14 +2184,14 @@ void __unlock_page_memcg(struct mem_cgroup *memcg)
 }
 
 /**
- * unlock_page_memcg - unlock a page->mem_cgroup binding
+ * unlock_page_memcg - unlock a page and memcg binding
  * @page: the page
  */
 void unlock_page_memcg(struct page *page)
 {
 	struct page *head = compound_head(page);
 
-	__unlock_page_memcg(head->mem_cgroup);
+	__unlock_page_memcg(page_memcg(head));
 }
 EXPORT_SYMBOL(unlock_page_memcg);
 
@@ -2889,7 +2881,7 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
 
 static void commit_charge(struct page *page, struct mem_cgroup *memcg)
 {
-	VM_BUG_ON_PAGE(page->mem_cgroup, page);
+	VM_BUG_ON_PAGE(page_memcg(page), page);
 	/*
 	 * Any of the following ensures page's memcg stability:
 	 *
@@ -2898,7 +2890,7 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg)
 	 * - lock_page_memcg()
 	 * - exclusive reference
 	 */
-	page->mem_cgroup = memcg;
+	page->memcg_data = (unsigned long)memcg;
 }
 
 #ifdef CONFIG_MEMCG_KMEM
@@ -2913,8 +2905,7 @@ int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
 	if (!vec)
 		return -ENOMEM;
 
-	if (cmpxchg(&page->obj_cgroups, NULL,
-		    (struct obj_cgroup **) ((unsigned long)vec | 0x1UL)))
+	if (!set_page_objcgs(page, vec))
 		kfree(vec);
 	else
 		kmemleak_not_leak(vec);
@@ -2925,6 +2916,12 @@ int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
 /*
  * Returns a pointer to the memory cgroup to which the kernel object is charged.
  *
+ * A passed kernel object can be a slab object or a generic kernel page, so
+ * different mechanisms for getting the memory cgroup pointer should be used.
+ * In certain cases (e.g. kernel stacks or large kmallocs with SLUB) the caller
+ * can not know for sure how the kernel object is implemented.
+ * mem_cgroup_from_obj() can be safely used in such cases.
+ *
  * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(),
  * cgroup_mutex, etc.
  */
@@ -2938,35 +2935,30 @@ struct mem_cgroup *mem_cgroup_from_obj(void *p)
 	page = virt_to_head_page(p);
 
 	/*
-	 * If page->mem_cgroup is set, it's either a simple mem_cgroup pointer
-	 * or a pointer to obj_cgroup vector. In the latter case the lowest
-	 * bit of the pointer is set.
-	 * The page->mem_cgroup pointer can be asynchronously changed
-	 * from NULL to (obj_cgroup_vec | 0x1UL), but can't be changed
-	 * from a valid memcg pointer to objcg vector or back.
-	 */
-	if (!page->mem_cgroup)
-		return NULL;
-
-	/*
 	 * Slab objects are accounted individually, not per-page.
 	 * Memcg membership data for each individual object is saved in
 	 * the page->obj_cgroups.
 	 */
-	if (page_has_obj_cgroups(page)) {
+	if (page_objcgs_check(page)) {
 		struct obj_cgroup *objcg;
 		unsigned int off;
 
 		off = obj_to_index(page->slab_cache, page, p);
-		objcg = page_obj_cgroups(page)[off];
+		objcg = page_objcgs(page)[off];
 		if (objcg)
 			return obj_cgroup_memcg(objcg);
 
 		return NULL;
 	}
 
-	/* All other pages use page->mem_cgroup */
-	return page->mem_cgroup;
+	/*
+	 * page_memcg_check() is used here, because page_has_obj_cgroups()
+	 * check above could fail because the object cgroups vector wasn't set
+	 * at that moment, but it can be set concurrently.
+	 * page_memcg_check(page) will guarantee that a proper memory
+	 * cgroup pointer or NULL will be returned.
+	 */
+	return page_memcg_check(page);
 }
 
 __always_inline struct obj_cgroup *get_obj_cgroup_from_current(void)
@@ -3105,8 +3097,8 @@ int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order)
 	if (memcg && !mem_cgroup_is_root(memcg)) {
 		ret = __memcg_kmem_charge(memcg, gfp, 1 << order);
 		if (!ret) {
-			page->mem_cgroup = memcg;
-			__SetPageKmemcg(page);
+			page->memcg_data = (unsigned long)memcg |
+				MEMCG_DATA_KMEM;
 			return 0;
 		}
 		css_put(&memcg->css);
@@ -3121,7 +3113,7 @@ int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order)
  */
 void __memcg_kmem_uncharge_page(struct page *page, int order)
 {
-	struct mem_cgroup *memcg = page->mem_cgroup;
+	struct mem_cgroup *memcg = page_memcg(page);
 	unsigned int nr_pages = 1 << order;
 
 	if (!memcg)
@@ -3129,12 +3121,8 @@ void __memcg_kmem_uncharge_page(struct page *page, int order)
 
 	VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page);
 	__memcg_kmem_uncharge(memcg, nr_pages);
-	page->mem_cgroup = NULL;
+	page->memcg_data = 0;
 	css_put(&memcg->css);
-
-	/* slab pages do not have PageKmemcg flag set */
-	if (PageKmemcg(page))
-		__ClearPageKmemcg(page);
 }
 
 static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes)
@@ -3282,7 +3270,7 @@ void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size)
  */
 void mem_cgroup_split_huge_fixup(struct page *head)
 {
-	struct mem_cgroup *memcg = head->mem_cgroup;
+	struct mem_cgroup *memcg = page_memcg(head);
 	int i;
 
 	if (mem_cgroup_disabled())
@@ -3290,7 +3278,7 @@ void mem_cgroup_split_huge_fixup(struct page *head)
 
 	for (i = 1; i < HPAGE_PMD_NR; i++) {
 		css_get(&memcg->css);
-		head[i].mem_cgroup = memcg;
+		head[i].memcg_data = (unsigned long)memcg;
 	}
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
@@ -4631,7 +4619,7 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
 void mem_cgroup_track_foreign_dirty_slowpath(struct page *page,
 					     struct bdi_writeback *wb)
 {
-	struct mem_cgroup *memcg = page->mem_cgroup;
+	struct mem_cgroup *memcg = page_memcg(page);
 	struct memcg_cgwb_frn *frn;
 	u64 now = get_jiffies_64();
 	u64 oldest_at = now;
@@ -5592,14 +5580,14 @@ static int mem_cgroup_move_account(struct page *page,
 
 	/*
 	 * Prevent mem_cgroup_migrate() from looking at
-	 * page->mem_cgroup of its source page while we change it.
+	 * page's memory cgroup of its source page while we change it.
 	 */
 	ret = -EBUSY;
 	if (!trylock_page(page))
 		goto out;
 
 	ret = -EINVAL;
-	if (page->mem_cgroup != from)
+	if (page_memcg(page) != from)
 		goto out_unlock;
 
 	pgdat = page_pgdat(page);
@@ -5654,13 +5642,13 @@ static int mem_cgroup_move_account(struct page *page,
 	/*
 	 * All state has been migrated, let's switch to the new memcg.
 	 *
-	 * It is safe to change page->mem_cgroup here because the page
+	 * It is safe to change page's memcg here because the page
 	 * is referenced, charged, isolated, and locked: we can't race
 	 * with (un)charging, migration, LRU putback, or anything else
-	 * that would rely on a stable page->mem_cgroup.
+	 * that would rely on a stable page's memory cgroup.
 	 *
 	 * Note that lock_page_memcg is a memcg lock, not a page lock,
-	 * to save space. As soon as we switch page->mem_cgroup to a
+	 * to save space. As soon as we switch page's memory cgroup to a
 	 * new memcg that isn't locked, the above state can change
 	 * concurrently again. Make sure we're truly done with it.
 	 */
@@ -5669,7 +5657,7 @@ static int mem_cgroup_move_account(struct page *page,
 	css_get(&to->css);
 	css_put(&from->css);
 
-	page->mem_cgroup = to;
+	page->memcg_data = (unsigned long)to;
 
 	__unlock_page_memcg(from);
 
@@ -5735,7 +5723,7 @@ static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
 		 * mem_cgroup_move_account() checks the page is valid or
 		 * not under LRU exclusion.
 		 */
-		if (page->mem_cgroup == mc.from) {
+		if (page_memcg(page) == mc.from) {
 			ret = MC_TARGET_PAGE;
 			if (is_device_private_page(page))
 				ret = MC_TARGET_DEVICE;
@@ -5779,7 +5767,7 @@ static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
 	VM_BUG_ON_PAGE(!page || !PageHead(page), page);
 	if (!(mc.flags & MOVE_ANON))
 		return ret;
-	if (page->mem_cgroup == mc.from) {
+	if (page_memcg(page) == mc.from) {
 		ret = MC_TARGET_PAGE;
 		if (target) {
 			get_page(page);
@@ -6706,12 +6694,12 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask)
 		/*
 		 * Every swap fault against a single page tries to charge the
 		 * page, bail as early as possible.  shmem_unuse() encounters
-		 * already charged pages, too.  page->mem_cgroup is protected
-		 * by the page lock, which serializes swap cache removal, which
-		 * in turn serializes uncharging.
+		 * already charged pages, too.  page and memcg binding is
+		 * protected by the page lock, which serializes swap cache
+		 * removal, which in turn serializes uncharging.
 		 */
 		VM_BUG_ON_PAGE(!PageLocked(page), page);
-		if (compound_head(page)->mem_cgroup)
+		if (page_memcg(compound_head(page)))
 			goto out;
 
 		id = lookup_swap_cgroup_id(ent);
@@ -6795,21 +6783,21 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug)
 
 	VM_BUG_ON_PAGE(PageLRU(page), page);
 
-	if (!page->mem_cgroup)
+	if (!page_memcg(page))
 		return;
 
 	/*
 	 * Nobody should be changing or seriously looking at
-	 * page->mem_cgroup at this point, we have fully
+	 * page_memcg(page) at this point, we have fully
 	 * exclusive access to the page.
 	 */
 
-	if (ug->memcg != page->mem_cgroup) {
+	if (ug->memcg != page_memcg(page)) {
 		if (ug->memcg) {
 			uncharge_batch(ug);
 			uncharge_gather_clear(ug);
 		}
-		ug->memcg = page->mem_cgroup;
+		ug->memcg = page_memcg(page);
 
 		/* pairs with css_put in uncharge_batch */
 		css_get(&ug->memcg->css);
@@ -6818,15 +6806,13 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug)
 	nr_pages = compound_nr(page);
 	ug->nr_pages += nr_pages;
 
-	if (!PageKmemcg(page)) {
-		ug->pgpgout++;
-	} else {
+	if (PageMemcgKmem(page))
 		ug->nr_kmem += nr_pages;
-		__ClearPageKmemcg(page);
-	}
+	else
+		ug->pgpgout++;
 
 	ug->dummy_page = page;
-	page->mem_cgroup = NULL;
+	page->memcg_data = 0;
 	css_put(&ug->memcg->css);
 }
 
@@ -6869,7 +6855,7 @@ void mem_cgroup_uncharge(struct page *page)
 		return;
 
 	/* Don't touch page->lru of any random page, pre-check: */
-	if (!page->mem_cgroup)
+	if (!page_memcg(page))
 		return;
 
 	uncharge_gather_clear(&ug);
@@ -6919,10 +6905,10 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)
 		return;
 
 	/* Page cache replacement: new page already charged? */
-	if (newpage->mem_cgroup)
+	if (page_memcg(newpage))
 		return;
 
-	memcg = oldpage->mem_cgroup;
+	memcg = page_memcg(oldpage);
 	if (!memcg)
 		return;
 
@@ -7117,7 +7103,7 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
 	if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
 		return;
 
-	memcg = page->mem_cgroup;
+	memcg = page_memcg(page);
 
 	/* Readahead page, never charged */
 	if (!memcg)
@@ -7138,7 +7124,7 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
 	VM_BUG_ON_PAGE(oldid, page);
 	mod_memcg_state(swap_memcg, MEMCG_SWAP, nr_entries);
 
-	page->mem_cgroup = NULL;
+	page->memcg_data = 0;
 
 	if (!mem_cgroup_is_root(memcg))
 		page_counter_uncharge(&memcg->memory, nr_entries);
@@ -7181,7 +7167,7 @@ int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
 		return 0;
 
-	memcg = page->mem_cgroup;
+	memcg = page_memcg(page);
 
 	/* Readahead page, never charged */
 	if (!memcg)
@@ -7262,7 +7248,7 @@ bool mem_cgroup_swap_full(struct page *page)
 	if (cgroup_memory_noswap || !cgroup_subsys_on_dfl(memory_cgrp_subsys))
 		return false;
 
-	memcg = page->mem_cgroup;
+	memcg = page_memcg(page);
 	if (!memcg)
 		return false;
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b63294517e04..db37bf231e8b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1101,7 +1101,7 @@ static inline bool page_expected_state(struct page *page,
 	if (unlikely((unsigned long)page->mapping |
 			page_ref_count(page) |
 #ifdef CONFIG_MEMCG
-			(unsigned long)page->mem_cgroup |
+			(unsigned long)page_memcg(page) |
 #endif
 			(page->flags & check_flags)))
 		return false;
@@ -1126,7 +1126,7 @@ static const char *page_bad_reason(struct page *page, unsigned long flags)
 			bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
 	}
 #ifdef CONFIG_MEMCG
-	if (unlikely(page->mem_cgroup))
+	if (unlikely(page_memcg(page)))
 		bad_reason = "page still charged to cgroup";
 #endif
 	return bad_reason;
@@ -1223,7 +1223,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
 		 * Do not let hwpoison pages hit pcplists/buddy
 		 * Untie memcg state and reset page's owner
 		 */
-		if (memcg_kmem_enabled() && PageKmemcg(page))
+		if (memcg_kmem_enabled() && PageMemcgKmem(page))
 			__memcg_kmem_uncharge_page(page, order);
 		reset_page_owner(page, order);
 		return false;
@@ -1253,7 +1253,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
 	}
 	if (PageMappingFlags(page))
 		page->mapping = NULL;
-	if (memcg_kmem_enabled() && PageKmemcg(page))
+	if (memcg_kmem_enabled() && PageMemcgKmem(page))
 		__memcg_kmem_uncharge_page(page, order);
 	if (check_free)
 		bad += check_free_page(page);
diff --git a/mm/page_io.c b/mm/page_io.c
index 433df1263349..9bca17ecc4df 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -291,12 +291,14 @@ static inline void count_swpout_vm_event(struct page *page)
 static void bio_associate_blkg_from_page(struct bio *bio, struct page *page)
 {
 	struct cgroup_subsys_state *css;
+	struct mem_cgroup *memcg;
 
-	if (!page->mem_cgroup)
+	memcg = page_memcg(page);
+	if (!memcg)
 		return;
 
 	rcu_read_lock();
-	css = cgroup_e_css(page->mem_cgroup->css.cgroup, &io_cgrp_subsys);
+	css = cgroup_e_css(memcg->css.cgroup, &io_cgrp_subsys);
 	bio_associate_blkg_from_css(bio, css);
 	rcu_read_unlock();
 }
diff --git a/mm/slab.h b/mm/slab.h
index 54faf9a623f9..1a756a359fa8 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -239,30 +239,13 @@ static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t fla
 }
 
 #ifdef CONFIG_MEMCG_KMEM
-static inline struct obj_cgroup **page_obj_cgroups(struct page *page)
-{
-	/*
-	 * page->mem_cgroup and page->obj_cgroups are sharing the same
-	 * space. To distinguish between them in case we don't know for sure
-	 * that the page is a slab page (e.g. page_cgroup_ino()), let's
-	 * always set the lowest bit of obj_cgroups.
-	 */
-	return (struct obj_cgroup **)
-		((unsigned long)page->obj_cgroups & ~0x1UL);
-}
-
-static inline bool page_has_obj_cgroups(struct page *page)
-{
-	return ((unsigned long)page->obj_cgroups & 0x1UL);
-}
-
 int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
 				 gfp_t gfp);
 
 static inline void memcg_free_page_obj_cgroups(struct page *page)
 {
-	kfree(page_obj_cgroups(page));
-	page->obj_cgroups = NULL;
+	kfree(page_objcgs(page));
+	page->memcg_data = 0;
 }
 
 static inline size_t obj_full_size(struct kmem_cache *s)
@@ -333,7 +316,7 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
 		if (likely(p[i])) {
 			page = virt_to_head_page(p[i]);
 
-			if (!page_has_obj_cgroups(page) &&
+			if (!page_objcgs(page) &&
 			    memcg_alloc_page_obj_cgroups(page, s, flags)) {
 				obj_cgroup_uncharge(objcg, obj_full_size(s));
 				continue;
@@ -341,7 +324,7 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
 
 			off = obj_to_index(s, page, p[i]);
 			obj_cgroup_get(objcg);
-			page_obj_cgroups(page)[off] = objcg;
+			page_objcgs(page)[off] = objcg;
 			mod_objcg_state(objcg, page_pgdat(page),
 					cache_vmstat_idx(s), obj_full_size(s));
 		} else {
@@ -355,6 +338,7 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
 					void **p, int objects)
 {
 	struct kmem_cache *s;
+	struct obj_cgroup **objcgs;
 	struct obj_cgroup *objcg;
 	struct page *page;
 	unsigned int off;
@@ -368,7 +352,8 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
 			continue;
 
 		page = virt_to_head_page(p[i]);
-		if (!page_has_obj_cgroups(page))
+		objcgs = page_objcgs(page);
+		if (!objcgs)
 			continue;
 
 		if (!s_orig)
@@ -377,11 +362,11 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
 			s = s_orig;
 
 		off = obj_to_index(s, page, p[i]);
-		objcg = page_obj_cgroups(page)[off];
+		objcg = objcgs[off];
 		if (!objcg)
 			continue;
 
-		page_obj_cgroups(page)[off] = NULL;
+		objcgs[off] = NULL;
 		obj_cgroup_uncharge(objcg, obj_full_size(s));
 		mod_objcg_state(objcg, page_pgdat(page), cache_vmstat_idx(s),
 				-obj_full_size(s));
@@ -390,11 +375,6 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
 }
 
 #else /* CONFIG_MEMCG_KMEM */
-static inline bool page_has_obj_cgroups(struct page *page)
-{
-	return false;
-}
-
 static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
 {
 	return NULL;
diff --git a/mm/workingset.c b/mm/workingset.c
index 25f75bbe80e0..9abe51d51aa7 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -257,7 +257,7 @@ void *workingset_eviction(struct page *page, struct mem_cgroup *target_memcg)
 	struct lruvec *lruvec;
 	int memcgid;
 
-	/* Page is fully exclusive and pins page->mem_cgroup */
+	/* Page is fully exclusive and pins page's memory cgroup pointer */
 	VM_BUG_ON_PAGE(PageLRU(page), page);
 	VM_BUG_ON_PAGE(page_count(page), page);
 	VM_BUG_ON_PAGE(!PageLocked(page), page);