Re: [PATCH v20 18/20] mm/lru: replace pgdat lru_lock with lruvec lock

Alex Shi
2020-10-30T02:51:59Z

patch changed since variable renaming in 04th patch:

From e892e74a35c27e69bebb73d2e4cff54e438f8d7d Mon Sep 17 00:00:00 2001
From: Alex Shi <alex.shi@linux.alibaba.com>
Date: Tue, 18 Aug 2020 16:44:21 +0800
Subject: [PATCH v21 18/20] mm/lru: replace pgdat lru_lock with lruvec lock

This patch moves per node lru_lock into lruvec, thus bring a lru_lock for
each of memcg per node. So on a large machine, each of memcg don't
have to suffer from per node pgdat->lru_lock competition. They could go
fast with their self lru_lock.

After move memcg charge before lru inserting, page isolation could
serialize page's memcg, then per memcg lruvec lock is stable and could
replace per node lru lock.

In func isolate_migratepages_block, compact_unlock_should_abort and
lock_page_lruvec_irqsave are open coded to work with compact_control.
Also add a debug func in locking which may give some clues if there are
sth out of hands.

Daniel Jordan's testing show 62% improvement on modified readtwice case
on his 2P * 10 core * 2 HT broadwell box.
https://lore.kernel.org/lkml/20200915165807.kpp7uhiw7l3loofu@ca-dmjordan1.us.oracle.com/

On a large machine with memcg enabled but not used, the page's lruvec
seeking pass a few pointers, that may lead to lru_lock holding time
increase and a bit regression.

Hugh Dickins helped on the patch polish, thanks!

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Rong Chen <rong.a.chen@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: cgroups@vger.kernel.org
---
include/linux/memcontrol.h | 58 +++++++++++++++++++++++++
include/linux/mmzone.h | 3 +-
mm/compaction.c | 56 +++++++++++++++---------
mm/huge_memory.c | 11 ++---
mm/memcontrol.c | 62 ++++++++++++++++++++++++--
mm/mlock.c | 22 +++++++---
mm/mmzone.c | 1 +
mm/page_alloc.c | 1 -
mm/swap.c | 105 +++++++++++++++++++++------------------------
mm/vmscan.c | 55 +++++++++++-------------
10 files changed, 249 insertions(+), 125 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index e391e3c56de5..f447a1bfa654 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -497,6 +497,19 @@ static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,

struct mem_cgroup *get_mem_cgroup_from_page(struct page *page);

+struct lruvec *lock_page_lruvec(struct page *page);
+struct lruvec *lock_page_lruvec_irq(struct page *page);
+struct lruvec *lock_page_lruvec_irqsave(struct page *page,
+ unsigned long *flags);
+
+#ifdef CONFIG_DEBUG_VM
+void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page);
+#else
+static inline void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page)
+{
+}
+#endif
+
static inline
struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css){
return css ? container_of(css, struct mem_cgroup, css) : NULL;
@@ -1038,6 +1051,31 @@ static inline void mem_cgroup_put(struct mem_cgroup *memcg)
{
}

+static inline struct lruvec *lock_page_lruvec(struct page *page)
+{
+ struct pglist_data *pgdat = page_pgdat(page);
+
+ spin_lock(&pgdat->__lruvec.lru_lock);
+ return &pgdat->__lruvec;
+}
+
+static inline struct lruvec *lock_page_lruvec_irq(struct page *page)
+{
+ struct pglist_data *pgdat = page_pgdat(page);
+
+ spin_lock_irq(&pgdat->__lruvec.lru_lock);
+ return &pgdat->__lruvec;
+}
+
+static inline struct lruvec *lock_page_lruvec_irqsave(struct page *page,
+ unsigned long *flagsp)
+{
+ struct pglist_data *pgdat = page_pgdat(page);
+
+ spin_lock_irqsave(&pgdat->__lruvec.lru_lock, *flagsp);
+ return &pgdat->__lruvec;
+}
+
static inline struct mem_cgroup *
mem_cgroup_iter(struct mem_cgroup *root,
struct mem_cgroup *prev,
@@ -1285,6 +1323,10 @@ static inline void count_memcg_page_event(struct page *page,
void count_memcg_event_mm(struct mm_struct *mm, enum vm_event_item idx)
{
}
+
+static inline void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page)
+{
+}
#endif /* CONFIG_MEMCG */

/* idx can be of type enum memcg_stat_item or node_stat_item */
@@ -1414,6 +1456,22 @@ static inline struct lruvec *parent_lruvec(struct lruvec *lruvec)
return mem_cgroup_lruvec(memcg, lruvec_pgdat(lruvec));
}

+static inline void unlock_page_lruvec(struct lruvec *lruvec)
+{
+ spin_unlock(&lruvec->lru_lock);
+}
+
+static inline void unlock_page_lruvec_irq(struct lruvec *lruvec)
+{
+ spin_unlock_irq(&lruvec->lru_lock);
+}
+
+static inline void unlock_page_lruvec_irqrestore(struct lruvec *lruvec,
+ unsigned long flags)
+{
+ spin_unlock_irqrestore(&lruvec->lru_lock, flags);
+}
+
#ifdef CONFIG_CGROUP_WRITEBACK

struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index fb3bf696c05e..0afba4ea2a21 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -276,6 +276,8 @@ enum lruvec_flags {

struct lruvec {
struct list_head lists[NR_LRU_LISTS];
+ /* per lruvec lru_lock for memcg */
+ spinlock_t lru_lock;
/*
* These track the cost of reclaiming one LRU - file or anon -
* over the other. As the observed cost of reclaiming one LRU
@@ -796,7 +798,6 @@ struct deferred_split {

/* Write-intensive fields used by page reclaim */
ZONE_PADDING(_pad1_)
- spinlock_t lru_lock;

#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
/*
diff --git a/mm/compaction.c b/mm/compaction.c
index 75f7973605f4..a69784820324 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -804,7 +804,7 @@ static bool too_many_isolated(pg_data_t *pgdat)
unsigned long nr_scanned = 0, nr_isolated = 0;
struct lruvec *lruvec;
unsigned long flags = 0;
- bool locked = false;
+ struct lruvec *locked = NULL;
struct page *page = NULL, *valid_page = NULL;
unsigned long start_pfn = low_pfn;
bool skip_on_failure = false;
@@ -864,11 +864,20 @@ static bool too_many_isolated(pg_data_t *pgdat)
* contention, to give chance to IRQs. Abort completely if
* a fatal signal is pending.
*/
- if (!(low_pfn % SWAP_CLUSTER_MAX)
- && compact_unlock_should_abort(&pgdat->lru_lock,
- flags, &locked, cc)) {
- low_pfn = 0;
- goto fatal_pending;
+ if (!(low_pfn % SWAP_CLUSTER_MAX)) {
+ if (locked) {
+ unlock_page_lruvec_irqrestore(locked, flags);
+ locked = NULL;
+ }
+
+ if (fatal_signal_pending(current)) {
+ cc->contended = true;
+
+ low_pfn = 0;
+ goto fatal_pending;
+ }
+
+ cond_resched();
}

if (!pfn_valid_within(low_pfn))
@@ -940,9 +949,8 @@ static bool too_many_isolated(pg_data_t *pgdat)
if (unlikely(__PageMovable(page)) &&
!PageIsolated(page)) {
if (locked) {
- spin_unlock_irqrestore(&pgdat->lru_lock,
- flags);
- locked = false;
+ unlock_page_lruvec_irqrestore(locked, flags);
+ locked = NULL;
}

if (!isolate_movable_page(page, isolate_mode))
@@ -983,10 +991,19 @@ static bool too_many_isolated(pg_data_t *pgdat)
if (!TestClearPageLRU(page))
goto isolate_fail_put;

+ rcu_read_lock();
+ lruvec = mem_cgroup_page_lruvec(page, pgdat);
+
/* If we already hold the lock, we can skip some rechecking */
- if (!locked) {
- locked = compact_lock_irqsave(&pgdat->lru_lock,
- &flags, cc);
+ if (lruvec != locked) {
+ if (locked)
+ unlock_page_lruvec_irqrestore(locked, flags);
+
+ compact_lock_irqsave(&lruvec->lru_lock, &flags, cc);
+ locked = lruvec;
+ rcu_read_unlock();
+
+ lruvec_memcg_debug(lruvec, page);

/* Try get exclusive access under lock */
if (!skip_updated) {
@@ -1005,9 +1022,8 @@ static bool too_many_isolated(pg_data_t *pgdat)
SetPageLRU(page);
goto isolate_fail_put;
}
- }
-
- lruvec = mem_cgroup_page_lruvec(page, pgdat);
+ } else
+ rcu_read_unlock();

/* The whole page is taken off the LRU; skip the tail pages. */
if (PageCompound(page))
@@ -1041,8 +1057,8 @@ static bool too_many_isolated(pg_data_t *pgdat)
isolate_fail_put:
/* Avoid potential deadlock in freeing page under lru_lock */
if (locked) {
- spin_unlock_irqrestore(&pgdat->lru_lock, flags);
- locked = false;
+ unlock_page_lruvec_irqrestore(locked, flags);
+ locked = NULL;
}
put_page(page);

@@ -1057,8 +1073,8 @@ static bool too_many_isolated(pg_data_t *pgdat)
*/
if (nr_isolated) {
if (locked) {
- spin_unlock_irqrestore(&pgdat->lru_lock, flags);
- locked = false;
+ unlock_page_lruvec_irqrestore(locked, flags);
+ locked = NULL;
}
putback_movable_pages(&cc->migratepages);
cc->nr_migratepages = 0;
@@ -1086,7 +1102,7 @@ static bool too_many_isolated(pg_data_t *pgdat)

isolate_abort:
if (locked)
- spin_unlock_irqrestore(&pgdat->lru_lock, flags);
+ unlock_page_lruvec_irqrestore(locked, flags);
if (page) {
SetPageLRU(page);
put_page(page);
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 7811a30080fb..7b5da37895bd 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2352,7 +2352,7 @@ static void lru_add_page_tail(struct page *head, struct page *tail,
VM_BUG_ON_PAGE(!PageHead(head), head);
VM_BUG_ON_PAGE(PageCompound(tail), head);
VM_BUG_ON_PAGE(PageLRU(tail), head);
- lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
+ lockdep_assert_held(&lruvec->lru_lock);

if (list) {
/* page reclaim is reclaiming a huge page */
@@ -2436,7 +2436,6 @@ static void __split_huge_page(struct page *page, struct list_head *list,
pgoff_t end)
{
struct page *head = compound_head(page);
- pg_data_t *pgdat = page_pgdat(head);
struct lruvec *lruvec;
struct address_space *swap_cache = NULL;
unsigned long offset = 0;
@@ -2454,10 +2453,8 @@ static void __split_huge_page(struct page *page, struct list_head *list,
xa_lock(&swap_cache->i_pages);
}

- /* prevent PageLRU to go away from under us, and freeze lru stats */
- spin_lock(&pgdat->lru_lock);
-
- lruvec = mem_cgroup_page_lruvec(head, pgdat);
+ /* lock lru list/PageCompound, ref freezed by page_ref_freeze */
+ lruvec = lock_page_lruvec(head);

for (i = nr - 1; i >= 1; i--) {
__split_huge_page_tail(head, i, lruvec, list);
@@ -2478,7 +2475,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
}

ClearPageCompound(head);
- spin_unlock(&pgdat->lru_lock);
+ unlock_page_lruvec(lruvec);
/* Caller disabled irqs, so they are still disabled here */

split_page_owner(head, nr);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 599aa8863111..0c97292834fa 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1330,6 +1330,19 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
return ret;
}

+#ifdef CONFIG_DEBUG_VM
+void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page)
+{
+ if (mem_cgroup_disabled())
+ return;
+
+ if (!page->mem_cgroup)
+ VM_BUG_ON_PAGE(lruvec_memcg(lruvec) != root_mem_cgroup, page);
+ else
+ VM_BUG_ON_PAGE(lruvec_memcg(lruvec) != page->mem_cgroup, page);
+}
+#endif
+
/**
* mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
* @page: the page
@@ -1367,6 +1380,51 @@ struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct pglist_data *pgd
return lruvec;
}

+struct lruvec *lock_page_lruvec(struct page *page)
+{
+ struct lruvec *lruvec;
+ struct pglist_data *pgdat = page_pgdat(page);
+
+ rcu_read_lock();
+ lruvec = mem_cgroup_page_lruvec(page, pgdat);
+ spin_lock(&lruvec->lru_lock);
+ rcu_read_unlock();
+
+ lruvec_memcg_debug(lruvec, page);
+
+ return lruvec;
+}
+
+struct lruvec *lock_page_lruvec_irq(struct page *page)
+{
+ struct lruvec *lruvec;
+ struct pglist_data *pgdat = page_pgdat(page);
+
+ rcu_read_lock();
+ lruvec = mem_cgroup_page_lruvec(page, pgdat);
+ spin_lock_irq(&lruvec->lru_lock);
+ rcu_read_unlock();
+
+ lruvec_memcg_debug(lruvec, page);
+
+ return lruvec;
+}
+
+struct lruvec *lock_page_lruvec_irqsave(struct page *page, unsigned long *flags)
+{
+ struct lruvec *lruvec;
+ struct pglist_data *pgdat = page_pgdat(page);
+
+ rcu_read_lock();
+ lruvec = mem_cgroup_page_lruvec(page, pgdat);
+ spin_lock_irqsave(&lruvec->lru_lock, *flags);
+ rcu_read_unlock();
+
+ lruvec_memcg_debug(lruvec, page);
+
+ return lruvec;
+}
+
/**
* mem_cgroup_update_lru_size - account for adding or removing an lru page
* @lruvec: mem_cgroup per zone lru vector
@@ -3270,10 +3328,8 @@ void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size)
#endif /* CONFIG_MEMCG_KMEM */

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-
/*
- * Because tail pages are not marked as "used", set it. We're under
- * pgdat->lru_lock and migration entries setup in all page mappings.
+ * Because page->mem_cgroup is not set on compound tails, set it now.
*/
void mem_cgroup_split_huge_fixup(struct page *head)
{
diff --git a/mm/mlock.c b/mm/mlock.c
index 7b0e6334be6f..ab164a675c25 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -262,12 +262,12 @@ static void __munlock_pagevec(struct pagevec *pvec, struct zone *zone)
int nr = pagevec_count(pvec);
int delta_munlocked = -nr;
struct pagevec pvec_putback;
+ struct lruvec *lruvec = NULL;
int pgrescued = 0;

pagevec_init(&pvec_putback);

/* Phase 1: page isolation */
- spin_lock_irq(&zone->zone_pgdat->lru_lock);
for (i = 0; i < nr; i++) {
struct page *page = pvec->pages[i];

@@ -277,10 +277,16 @@ static void __munlock_pagevec(struct pagevec *pvec, struct zone *zone)
* so we can spare the get_page() here.
*/
if (TestClearPageLRU(page)) {
- struct lruvec *lruvec;
+ struct lruvec *new_lruvec;
+
+ new_lruvec = mem_cgroup_page_lruvec(page,
+ page_pgdat(page));
+ if (new_lruvec != lruvec) {
+ if (lruvec)
+ unlock_page_lruvec_irq(lruvec);
+ lruvec = lock_page_lruvec_irq(page);
+ }

- lruvec = mem_cgroup_page_lruvec(page,
- page_pgdat(page));
del_page_from_lru_list(page, lruvec,
page_lru(page));
continue;
@@ -299,8 +305,12 @@ static void __munlock_pagevec(struct pagevec *pvec, struct zone *zone)
pagevec_add(&pvec_putback, pvec->pages[i]);
pvec->pages[i] = NULL;
}
- __mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
- spin_unlock_irq(&zone->zone_pgdat->lru_lock);
+ if (lruvec) {
+ __mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
+ unlock_page_lruvec_irq(lruvec);
+ } else if (delta_munlocked) {
+ mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
+ }

/* Now we can release pins of pages that we are not munlocking */
pagevec_release(&pvec_putback);
diff --git a/mm/mmzone.c b/mm/mmzone.c
index 4686fdc23bb9..3750a90ed4a0 100644
--- a/mm/mmzone.c
+++ b/mm/mmzone.c
@@ -91,6 +91,7 @@ void lruvec_init(struct lruvec *lruvec)
enum lru_list lru;

memset(lruvec, 0, sizeof(struct lruvec));
+ spin_lock_init(&lruvec->lru_lock);

for_each_lru(lru)
INIT_LIST_HEAD(&lruvec->lists[lru]);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 23f5066bd4a5..713e6554becd 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6791,7 +6791,6 @@ static void __meminit pgdat_init_internals(struct pglist_data *pgdat)
init_waitqueue_head(&pgdat->pfmemalloc_wait);

pgdat_page_ext_init(pgdat);
- spin_lock_init(&pgdat->lru_lock);
lruvec_init(&pgdat->__lruvec);
}

diff --git a/mm/swap.c b/mm/swap.c
index 9e30f096309b..580ea18a9596 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -79,16 +79,14 @@ static DEFINE_PER_CPU(struct lru_pvecs, lru_pvecs) = {
static void __page_cache_release(struct page *page)
{
if (PageLRU(page)) {
- pg_data_t *pgdat = page_pgdat(page);
struct lruvec *lruvec;
unsigned long flags;

- spin_lock_irqsave(&pgdat->lru_lock, flags);
- lruvec = mem_cgroup_page_lruvec(page, pgdat);
+ lruvec = lock_page_lruvec_irqsave(page, &flags);
VM_BUG_ON_PAGE(!PageLRU(page), page);
__ClearPageLRU(page);
del_page_from_lru_list(page, lruvec, page_off_lru(page));
- spin_unlock_irqrestore(&pgdat->lru_lock, flags);
+ unlock_page_lruvec_irqrestore(lruvec, flags);
}
__ClearPageWaiters(page);
}
@@ -207,32 +205,30 @@ static void pagevec_lru_move_fn(struct pagevec *pvec,
void (*move_fn)(struct page *page, struct lruvec *lruvec))
{
int i;
- struct pglist_data *pgdat = NULL;
- struct lruvec *lruvec;
+ struct lruvec *lruvec = NULL;
unsigned long flags = 0;

for (i = 0; i < pagevec_count(pvec); i++) {
struct page *page = pvec->pages[i];
- struct pglist_data *pagepgdat = page_pgdat(page);
-
- if (pagepgdat != pgdat) {
- if (pgdat)
- spin_unlock_irqrestore(&pgdat->lru_lock, flags);
- pgdat = pagepgdat;
- spin_lock_irqsave(&pgdat->lru_lock, flags);
- }
+ struct lruvec *new_lruvec;

/* block memcg migration during page moving between lru */
if (!TestClearPageLRU(page))
continue;

- lruvec = mem_cgroup_page_lruvec(page, pgdat);
+ new_lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page));
+ if (lruvec != new_lruvec) {
+ if (lruvec)
+ unlock_page_lruvec_irqrestore(lruvec, flags);
+ lruvec = lock_page_lruvec_irqsave(page, &flags);
+ }
+
(*move_fn)(page, lruvec);

SetPageLRU(page);
}
- if (pgdat)
- spin_unlock_irqrestore(&pgdat->lru_lock, flags);
+ if (lruvec)
+ unlock_page_lruvec_irqrestore(lruvec, flags);
release_pages(pvec->pages, pvec->nr);
pagevec_reinit(pvec);
}
@@ -274,9 +270,8 @@ void lru_note_cost(struct lruvec *lruvec, bool file, unsigned int nr_pages)
{
do {
unsigned long lrusize;
- struct pglist_data *pgdat = lruvec_pgdat(lruvec);

- spin_lock_irq(&pgdat->lru_lock);
+ spin_lock_irq(&lruvec->lru_lock);
/* Record cost event */
if (file)
lruvec->file_cost += nr_pages;
@@ -300,7 +295,7 @@ void lru_note_cost(struct lruvec *lruvec, bool file, unsigned int nr_pages)
lruvec->file_cost /= 2;
lruvec->anon_cost /= 2;
}
- spin_unlock_irq(&pgdat->lru_lock);
+ spin_unlock_irq(&lruvec->lru_lock);
} while ((lruvec = parent_lruvec(lruvec)));
}

@@ -364,13 +359,13 @@ static inline void activate_page_drain(int cpu)

static void activate_page(struct page *page)
{
- pg_data_t *pgdat = page_pgdat(page);
+ struct lruvec *lruvec;

page = compound_head(page);
- spin_lock_irq(&pgdat->lru_lock);
+ lruvec = lock_page_lruvec_irq(page);
if (PageLRU(page))
- __activate_page(page, mem_cgroup_page_lruvec(page, pgdat));
- spin_unlock_irq(&pgdat->lru_lock);
+ __activate_page(page, lruvec);
+ unlock_page_lruvec_irq(lruvec);
}
#endif

@@ -860,8 +855,7 @@ void release_pages(struct page **pages, int nr)
{
int i;
LIST_HEAD(pages_to_free);
- struct pglist_data *locked_pgdat = NULL;
- struct lruvec *lruvec;
+ struct lruvec *lruvec = NULL;
unsigned long flags;
unsigned int lock_batch;

@@ -871,11 +865,11 @@ void release_pages(struct page **pages, int nr)
/*
* Make sure the IRQ-safe lock-holding time does not get
* excessive with a continuous string of pages from the
- * same pgdat. The lock is held only if pgdat != NULL.
+ * same lruvec. The lock is held only if lruvec != NULL.
*/
- if (locked_pgdat && ++lock_batch == SWAP_CLUSTER_MAX) {
- spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags);
- locked_pgdat = NULL;
+ if (lruvec && ++lock_batch == SWAP_CLUSTER_MAX) {
+ unlock_page_lruvec_irqrestore(lruvec, flags);
+ lruvec = NULL;
}

page = compound_head(page);
@@ -883,10 +877,9 @@ void release_pages(struct page **pages, int nr)
continue;

if (is_zone_device_page(page)) {
- if (locked_pgdat) {
- spin_unlock_irqrestore(&locked_pgdat->lru_lock,
- flags);
- locked_pgdat = NULL;
+ if (lruvec) {
+ unlock_page_lruvec_irqrestore(lruvec, flags);
+ lruvec = NULL;
}
/*
* ZONE_DEVICE pages that return 'false' from
@@ -904,27 +897,27 @@ void release_pages(struct page **pages, int nr)
continue;

if (PageCompound(page)) {
- if (locked_pgdat) {
- spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags);
- locked_pgdat = NULL;
+ if (lruvec) {
+ unlock_page_lruvec_irqrestore(lruvec, flags);
+ lruvec = NULL;
}
__put_compound_page(page);
continue;
}

if (PageLRU(page)) {
- struct pglist_data *pgdat = page_pgdat(page);
+ struct lruvec *new_lruvec;

- if (pgdat != locked_pgdat) {
- if (locked_pgdat)
- spin_unlock_irqrestore(&locked_pgdat->lru_lock,
+ new_lruvec = mem_cgroup_page_lruvec(page,
+ page_pgdat(page));
+ if (new_lruvec != lruvec) {
+ if (lruvec)
+ unlock_page_lruvec_irqrestore(lruvec,
flags);
lock_batch = 0;
- locked_pgdat = pgdat;
- spin_lock_irqsave(&locked_pgdat->lru_lock, flags);
+ lruvec = lock_page_lruvec_irqsave(page, &flags);
}

- lruvec = mem_cgroup_page_lruvec(page, locked_pgdat);
VM_BUG_ON_PAGE(!PageLRU(page), page);
__ClearPageLRU(page);
del_page_from_lru_list(page, lruvec, page_off_lru(page));
@@ -934,8 +927,8 @@ void release_pages(struct page **pages, int nr)

list_add(&page->lru, &pages_to_free);
}
- if (locked_pgdat)
- spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags);
+ if (lruvec)
+ unlock_page_lruvec_irqrestore(lruvec, flags);

mem_cgroup_uncharge_list(&pages_to_free);
free_unref_page_list(&pages_to_free);
@@ -1023,26 +1016,24 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec)
void __pagevec_lru_add(struct pagevec *pvec)
{
int i;
- struct pglist_data *pgdat = NULL;
- struct lruvec *lruvec;
+ struct lruvec *lruvec = NULL;
unsigned long flags = 0;

for (i = 0; i < pagevec_count(pvec); i++) {
struct page *page = pvec->pages[i];
- struct pglist_data *pagepgdat = page_pgdat(page);
+ struct lruvec *new_lruvec;

- if (pagepgdat != pgdat) {
- if (pgdat)
- spin_unlock_irqrestore(&pgdat->lru_lock, flags);
- pgdat = pagepgdat;
- spin_lock_irqsave(&pgdat->lru_lock, flags);
+ new_lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page));
+ if (lruvec != new_lruvec) {
+ if (lruvec)
+ unlock_page_lruvec_irqrestore(lruvec, flags);
+ lruvec = lock_page_lruvec_irqsave(page, &flags);
}

- lruvec = mem_cgroup_page_lruvec(page, pgdat);
__pagevec_lru_add_fn(page, lruvec);
}
- if (pgdat)
- spin_unlock_irqrestore(&pgdat->lru_lock, flags);
+ if (lruvec)
+ unlock_page_lruvec_irqrestore(lruvec, flags);
release_pages(pvec->pages, pvec->nr);
pagevec_reinit(pvec);
}
diff --git a/mm/vmscan.c b/mm/vmscan.c
index e28df9cb5be3..9e726b587d74 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1765,14 +1765,12 @@ int isolate_lru_page(struct page *page)
WARN_RATELIMIT(PageTail(page), "trying to isolate tail page");

if (TestClearPageLRU(page)) {
- pg_data_t *pgdat = page_pgdat(page);
struct lruvec *lruvec;

get_page(page);
- lruvec = mem_cgroup_page_lruvec(page, pgdat);
- spin_lock_irq(&pgdat->lru_lock);
+ lruvec = lock_page_lruvec_irq(page);
del_page_from_lru_list(page, lruvec, page_lru(page));
- spin_unlock_irq(&pgdat->lru_lock);
+ unlock_page_lruvec_irq(lruvec);
ret = 0;
}

@@ -1839,7 +1837,6 @@ static int too_many_isolated(struct pglist_data *pgdat, int file,
static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
struct list_head *list)
{
- struct pglist_data *pgdat = lruvec_pgdat(lruvec);
int nr_pages, nr_moved = 0;
LIST_HEAD(pages_to_free);
struct page *page;
@@ -1850,9 +1847,9 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
VM_BUG_ON_PAGE(PageLRU(page), page);
list_del(&page->lru);
if (unlikely(!page_evictable(page))) {
- spin_unlock_irq(&pgdat->lru_lock);
+ spin_unlock_irq(&lruvec->lru_lock);
putback_lru_page(page);
- spin_lock_irq(&pgdat->lru_lock);
+ spin_lock_irq(&lruvec->lru_lock);
continue;
}

@@ -1874,9 +1871,9 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
__ClearPageActive(page);

if (unlikely(PageCompound(page))) {
- spin_unlock_irq(&pgdat->lru_lock);
+ spin_unlock_irq(&lruvec->lru_lock);
destroy_compound_page(page);
- spin_lock_irq(&pgdat->lru_lock);
+ spin_lock_irq(&lruvec->lru_lock);
} else
list_add(&page->lru, &pages_to_free);

@@ -1949,7 +1946,7 @@ static int current_may_throttle(void)

lru_add_drain();

- spin_lock_irq(&pgdat->lru_lock);
+ spin_lock_irq(&lruvec->lru_lock);

nr_taken = isolate_lru_pages(nr_to_scan, lruvec, &page_list,
&nr_scanned, sc, lru);
@@ -1961,7 +1958,7 @@ static int current_may_throttle(void)
__count_memcg_events(lruvec_memcg(lruvec), item, nr_scanned);
__count_vm_events(PGSCAN_ANON + file, nr_scanned);

- spin_unlock_irq(&pgdat->lru_lock);
+ spin_unlock_irq(&lruvec->lru_lock);

if (nr_taken == 0)
return 0;
@@ -1969,7 +1966,7 @@ static int current_may_throttle(void)
nr_reclaimed = shrink_page_list(&page_list, pgdat, sc, 0,
&stat, false);

- spin_lock_irq(&pgdat->lru_lock);
+ spin_lock_irq(&lruvec->lru_lock);
move_pages_to_lru(lruvec, &page_list);

__mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken);
@@ -1978,7 +1975,7 @@ static int current_may_throttle(void)
__count_vm_events(item, nr_reclaimed);
__count_memcg_events(lruvec_memcg(lruvec), item, nr_reclaimed);
__count_vm_events(PGSTEAL_ANON + file, nr_reclaimed);
- spin_unlock_irq(&pgdat->lru_lock);
+ spin_unlock_irq(&lruvec->lru_lock);

lru_note_cost(lruvec, file, stat.nr_pageout);
mem_cgroup_uncharge_list(&page_list);
@@ -2031,7 +2028,7 @@ static void shrink_active_list(unsigned long nr_to_scan,

lru_add_drain();

- spin_lock_irq(&pgdat->lru_lock);
+ spin_lock_irq(&lruvec->lru_lock);

nr_taken = isolate_lru_pages(nr_to_scan, lruvec, &l_hold,
&nr_scanned, sc, lru);
@@ -2042,7 +2039,7 @@ static void shrink_active_list(unsigned long nr_to_scan,
__count_vm_events(PGREFILL, nr_scanned);
__count_memcg_events(lruvec_memcg(lruvec), PGREFILL, nr_scanned);

- spin_unlock_irq(&pgdat->lru_lock);
+ spin_unlock_irq(&lruvec->lru_lock);

while (!list_empty(&l_hold)) {
cond_resched();
@@ -2088,7 +2085,7 @@ static void shrink_active_list(unsigned long nr_to_scan,
/*
* Move pages back to the lru list.
*/
- spin_lock_irq(&pgdat->lru_lock);
+ spin_lock_irq(&lruvec->lru_lock);

nr_activate = move_pages_to_lru(lruvec, &l_active);
nr_deactivate = move_pages_to_lru(lruvec, &l_inactive);
@@ -2099,7 +2096,7 @@ static void shrink_active_list(unsigned long nr_to_scan,
__count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE, nr_deactivate);

__mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken);
- spin_unlock_irq(&pgdat->lru_lock);
+ spin_unlock_irq(&lruvec->lru_lock);

mem_cgroup_uncharge_list(&l_active);
free_unref_page_list(&l_active);
@@ -2689,10 +2686,10 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc)
/*
* Determine the scan balance between anon and file LRUs.
*/
- spin_lock_irq(&pgdat->lru_lock);
+ spin_lock_irq(&target_lruvec->lru_lock);
sc->anon_cost = target_lruvec->anon_cost;
sc->file_cost = target_lruvec->file_cost;
- spin_unlock_irq(&pgdat->lru_lock);
+ spin_unlock_irq(&target_lruvec->lru_lock);

/*
* Target desirable inactive:active list ratios for the anon
@@ -4268,16 +4265,15 @@ int node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned int order)
*/
void check_move_unevictable_pages(struct pagevec *pvec)
{
- struct lruvec *lruvec;
- struct pglist_data *pgdat = NULL;
+ struct lruvec *lruvec = NULL;
int pgscanned = 0;
int pgrescued = 0;
int i;

for (i = 0; i < pvec->nr; i++) {
struct page *page = pvec->pages[i];
- struct pglist_data *pagepgdat = page_pgdat(page);
int nr_pages;
+ struct lruvec *new_lruvec;

if (PageTransTail(page))
continue;
@@ -4289,13 +4285,12 @@ void check_move_unevictable_pages(struct pagevec *pvec)
if (!TestClearPageLRU(page))
continue;

- if (pagepgdat != pgdat) {
- if (pgdat)
- spin_unlock_irq(&pgdat->lru_lock);
- pgdat = pagepgdat;
- spin_lock_irq(&pgdat->lru_lock);
+ new_lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page));
+ if (lruvec != new_lruvec) {
+ if (lruvec)
+ unlock_page_lruvec_irq(lruvec);
+ lruvec = lock_page_lruvec_irq(page);
}
- lruvec = mem_cgroup_page_lruvec(page, pgdat);

if (page_evictable(page) && PageUnevictable(page)) {
enum lru_list lru = page_lru_base_type(page);
@@ -4309,10 +4304,10 @@ void check_move_unevictable_pages(struct pagevec *pvec)
SetPageLRU(page);
}

- if (pgdat) {
+ if (lruvec) {
__count_vm_events(UNEVICTABLE_PGRESCUED, pgrescued);
__count_vm_events(UNEVICTABLE_PGSCANNED, pgscanned);
- spin_unlock_irq(&pgdat->lru_lock);
+ unlock_page_lruvec_irq(lruvec);
} else if (pgscanned) {
count_vm_events(UNEVICTABLE_PGSCANNED, pgscanned);
}
--
1.8.3.1