diff options
| -rw-r--r-- | Documentation/admin-guide/cgroup-v1/memcg_test.rst | 15 | ||||
| -rw-r--r-- | Documentation/admin-guide/cgroup-v1/memory.rst | 21 | ||||
| -rw-r--r-- | Documentation/trace/events-kmem.rst | 2 | ||||
| -rw-r--r-- | Documentation/vm/unevictable-lru.rst | 22 | ||||
| -rw-r--r-- | include/linux/memcontrol.h | 110 | ||||
| -rw-r--r-- | include/linux/mm_types.h | 2 | ||||
| -rw-r--r-- | include/linux/mmzone.h | 6 | ||||
| -rw-r--r-- | include/linux/page-flags.h | 1 | ||||
| -rw-r--r-- | include/linux/swap.h | 4 | ||||
| -rw-r--r-- | mm/compaction.c | 94 | ||||
| -rw-r--r-- | mm/filemap.c | 4 | ||||
| -rw-r--r-- | mm/huge_memory.c | 45 | ||||
| -rw-r--r-- | mm/memcontrol.c | 84 | ||||
| -rw-r--r-- | mm/mlock.c | 63 | ||||
| -rw-r--r-- | mm/mmzone.c | 1 | ||||
| -rw-r--r-- | mm/page_alloc.c | 1 | ||||
| -rw-r--r-- | mm/page_idle.c | 4 | ||||
| -rw-r--r-- | mm/rmap.c | 12 | ||||
| -rw-r--r-- | mm/swap.c | 208 | ||||
| -rw-r--r-- | mm/vmscan.c | 207 | ||||
| -rw-r--r-- | mm/workingset.c | 2 |
21 files changed, 536 insertions, 372 deletions
diff --git a/Documentation/admin-guide/cgroup-v1/memcg_test.rst b/Documentation/admin-guide/cgroup-v1/memcg_test.rst index 4f83de2dab6e..45b94f7b3beb 100644 --- a/Documentation/admin-guide/cgroup-v1/memcg_test.rst +++ b/Documentation/admin-guide/cgroup-v1/memcg_test.rst @@ -133,18 +133,9 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y. 8. LRU ====== - Each memcg has its own private LRU. Now, its handling is under global - VM's control (means that it's handled under global pgdat->lru_lock). - Almost all routines around memcg's LRU is called by global LRU's - list management functions under pgdat->lru_lock. - - A special function is mem_cgroup_isolate_pages(). This scans - memcg's private LRU and call __isolate_lru_page() to extract a page - from LRU. - - (By __isolate_lru_page(), the page is removed from both of global and - private LRU.) - + Each memcg has its own vector of LRUs (inactive anon, active anon, + inactive file, active file, unevictable) of pages from each node, + each LRU handled under a single lru_lock for that memcg and node. 9. Typical Tests. ================= diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst index a44cd467d218..52688ae34461 100644 --- a/Documentation/admin-guide/cgroup-v1/memory.rst +++ b/Documentation/admin-guide/cgroup-v1/memory.rst @@ -287,20 +287,17 @@ When oom event notifier is registered, event will be delivered. 2.6 Locking ----------- - lock_page_cgroup()/unlock_page_cgroup() should not be called under - the i_pages lock. +Lock order is as follows: - Other lock order is following: + Page lock (PG_locked bit of page->flags) + mm->page_table_lock or split pte_lock + lock_page_memcg (memcg->move_lock) + mapping->i_pages lock + lruvec->lru_lock. - PG_locked. - mm->page_table_lock - pgdat->lru_lock - lock_page_cgroup. - - In many cases, just lock_page_cgroup() is called. - - per-zone-per-cgroup LRU (cgroup's private LRU) is just guarded by - pgdat->lru_lock, it has no lock of its own. +Per-node-per-memcgroup LRU (cgroup's private LRU) is guarded by +lruvec->lru_lock; PG_lru bit of page->flags is cleared before +isolating a page from its LRU under lruvec->lru_lock. 2.7 Kernel Memory Extension (CONFIG_MEMCG_KMEM) ----------------------------------------------- diff --git a/Documentation/trace/events-kmem.rst b/Documentation/trace/events-kmem.rst index 555484110e36..68fa75247488 100644 --- a/Documentation/trace/events-kmem.rst +++ b/Documentation/trace/events-kmem.rst @@ -69,7 +69,7 @@ When pages are freed in batch, the also mm_page_free_batched is triggered. Broadly speaking, pages are taken off the LRU lock in bulk and freed in batch with a page list. Significant amounts of activity here could indicate that the system is under memory pressure and can also indicate -contention on the zone->lru_lock. +contention on the lruvec->lru_lock. 4. Per-CPU Allocator Activity ============================= diff --git a/Documentation/vm/unevictable-lru.rst b/Documentation/vm/unevictable-lru.rst index 17d0861b0f1d..0e1490524f53 100644 --- a/Documentation/vm/unevictable-lru.rst +++ b/Documentation/vm/unevictable-lru.rst @@ -33,7 +33,7 @@ reclaim in Linux. The problems have been observed at customer sites on large memory x86_64 systems. To illustrate this with an example, a non-NUMA x86_64 platform with 128GB of -main memory will have over 32 million 4k pages in a single zone. When a large +main memory will have over 32 million 4k pages in a single node. When a large fraction of these pages are not evictable for any reason [see below], vmscan will spend a lot of time scanning the LRU lists looking for the small fraction of pages that are evictable. This can result in a situation where all CPUs are @@ -55,7 +55,7 @@ unevictable, either by definition or by circumstance, in the future. The Unevictable Page List ------------------------- -The Unevictable LRU infrastructure consists of an additional, per-zone, LRU list +The Unevictable LRU infrastructure consists of an additional, per-node, LRU list called the "unevictable" list and an associated page flag, PG_unevictable, to indicate that the page is being managed on the unevictable list. @@ -84,15 +84,9 @@ The unevictable list does not differentiate between file-backed and anonymous, swap-backed pages. This differentiation is only important while the pages are, in fact, evictable. -The unevictable list benefits from the "arrayification" of the per-zone LRU +The unevictable list benefits from the "arrayification" of the per-node LRU lists and statistics originally proposed and posted by Christoph Lameter. -The unevictable list does not use the LRU pagevec mechanism. Rather, -unevictable pages are placed directly on the page's zone's unevictable list -under the zone lru_lock. This allows us to prevent the stranding of pages on -the unevictable list when one task has the page isolated from the LRU and other -tasks are changing the "evictability" state of the page. - Memory Control Group Interaction -------------------------------- @@ -101,8 +95,8 @@ The unevictable LRU facility interacts with the memory control group [aka memory controller; see Documentation/admin-guide/cgroup-v1/memory.rst] by extending the lru_list enum. -The memory controller data structure automatically gets a per-zone unevictable -list as a result of the "arrayification" of the per-zone LRU lists (one per +The memory controller data structure automatically gets a per-node unevictable +list as a result of the "arrayification" of the per-node LRU lists (one per lru_list enum element). The memory controller tracks the movement of pages to and from the unevictable list. @@ -196,7 +190,7 @@ for the sake of expediency, to leave a unevictable page on one of the regular active/inactive LRU lists for vmscan to deal with. vmscan checks for such pages in all of the shrink_{active|inactive|page}_list() functions and will "cull" such pages that it encounters: that is, it diverts those pages to the -unevictable list for the zone being scanned. +unevictable list for the node being scanned. There may be situations where a page is mapped into a VM_LOCKED VMA, but the page is not marked as PG_mlocked. Such pages will make it all the way to @@ -328,7 +322,7 @@ If the page was NOT already mlocked, mlock_vma_page() attempts to isolate the page from the LRU, as it is likely on the appropriate active or inactive list at that time. If the isolate_lru_page() succeeds, mlock_vma_page() will put back the page - by calling putback_lru_page() - which will notice that the page -is now mlocked and divert the page to the zone's unevictable list. If +is now mlocked and divert the page to the node's unevictable list. If mlock_vma_page() is unable to isolate the page from the LRU, vmscan will handle it later if and when it attempts to reclaim the page. @@ -603,7 +597,7 @@ Some examples of these unevictable pages on the LRU lists are: unevictable list in mlock_vma_page(). shrink_inactive_list() also diverts any unevictable pages that it finds on the -inactive lists to the appropriate zone's unevictable list. +inactive lists to the appropriate node's unevictable list. shrink_inactive_list() should only see SHM_LOCK'd pages that became SHM_LOCK'd after shrink_active_list() had moved them to the inactive list, or pages mapped diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index f5b4d710f099..08ed57e02b73 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -654,12 +654,41 @@ out: struct lruvec *mem_cgroup_page_lruvec(struct page *, struct pglist_data *); +static inline bool lruvec_holds_page_lru_lock(struct page *page, + struct lruvec *lruvec) +{ + pg_data_t *pgdat = page_pgdat(page); + const struct mem_cgroup *memcg; + struct mem_cgroup_per_node *mz; + + if (mem_cgroup_disabled()) + return lruvec == &pgdat->__lruvec; + + mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec); + memcg = page_memcg(page) ? : root_mem_cgroup; + + return lruvec->pgdat == pgdat && mz->memcg == memcg; +} + struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p); struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm); 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; @@ -1167,6 +1196,14 @@ static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page, return &pgdat->__lruvec; } +static inline bool lruvec_holds_page_lru_lock(struct page *page, + struct lruvec *lruvec) +{ + pg_data_t *pgdat = page_pgdat(page); + + return lruvec == &pgdat->__lruvec; +} + static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) { return NULL; @@ -1192,6 +1229,31 @@ 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, @@ -1411,6 +1473,10 @@ static inline 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 */ @@ -1492,6 +1558,50 @@ 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); +} + +/* Don't lock again iff page's lruvec locked */ +static inline struct lruvec *relock_page_lruvec_irq(struct page *page, + struct lruvec *locked_lruvec) +{ + if (locked_lruvec) { + if (lruvec_holds_page_lru_lock(page, locked_lruvec)) + return locked_lruvec; + + unlock_page_lruvec_irq(locked_lruvec); + } + + return lock_page_lruvec_irq(page); +} + +/* Don't lock again iff page's lruvec locked */ +static inline struct lruvec *relock_page_lruvec_irqsave(struct page *page, + struct lruvec *locked_lruvec, unsigned long *flags) +{ + if (locked_lruvec) { + if (lruvec_holds_page_lru_lock(page, locked_lruvec)) + return locked_lruvec; + + unlock_page_lruvec_irqrestore(locked_lruvec, *flags); + } + + return lock_page_lruvec_irqsave(page, flags); +} + #ifdef CONFIG_CGROUP_WRITEBACK struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb); diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index e7de072ade03..07d9acb5b19c 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -79,7 +79,7 @@ struct page { struct { /* Page cache and anonymous pages */ /** * @lru: Pageout list, eg. active_list protected by - * pgdat->lru_lock. Sometimes used as a generic list + * lruvec->lru_lock. Sometimes used as a generic list * by the page owner. */ struct list_head lru; diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 98a80c01d150..b593316bff3d 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -113,8 +113,7 @@ static inline bool free_area_empty(struct free_area *area, int migratetype) struct pglist_data; /* - * zone->lock and the zone lru_lock are two of the hottest locks in the kernel. - * So add a wild amount of padding here to ensure that they fall into separate + * Add a wild amount of padding here to ensure datas fall into separate * cachelines. There are very few zone structures in the machine, so space * consumption is not a concern here. */ @@ -276,6 +275,8 @@ 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 @@ -782,7 +783,6 @@ typedef struct pglist_data { /* Write-intensive fields used by page reclaim */ ZONE_PADDING(_pad1_) - spinlock_t lru_lock; #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT /* diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index b5eb0fc15053..ec5d0290e0ee 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -334,6 +334,7 @@ PAGEFLAG(Referenced, referenced, PF_HEAD) PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) + TESTCLEARFLAG(LRU, lru, PF_HEAD) PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD) TESTCLEARFLAG(Active, active, PF_HEAD) PAGEFLAG(Workingset, workingset, PF_HEAD) diff --git a/include/linux/swap.h b/include/linux/swap.h index 667935c0dbd4..596bc2f4d9b0 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -338,8 +338,6 @@ extern void lru_note_cost(struct lruvec *lruvec, bool file, unsigned int nr_pages); extern void lru_note_cost_page(struct page *); extern void lru_cache_add(struct page *); -extern void lru_add_page_tail(struct page *page, struct page *page_tail, - struct lruvec *lruvec, struct list_head *head); extern void mark_page_accessed(struct page *); extern void lru_add_drain(void); extern void lru_add_drain_cpu(int cpu); @@ -358,7 +356,7 @@ extern void lru_cache_add_inactive_or_unevictable(struct page *page, extern unsigned long zone_reclaimable_pages(struct zone *zone); extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, gfp_t gfp_mask, nodemask_t *mask); -extern int __isolate_lru_page(struct page *page, isolate_mode_t mode); +extern int __isolate_lru_page_prepare(struct page *page, isolate_mode_t mode); extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, unsigned long nr_pages, gfp_t gfp_mask, diff --git a/mm/compaction.c b/mm/compaction.c index dbcfdfce1b82..e5acb9714436 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -804,7 +804,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, 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; @@ -868,11 +868,20 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, * 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)) @@ -890,6 +899,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, if (!valid_page && IS_ALIGNED(low_pfn, pageblock_nr_pages)) { if (!cc->ignore_skip_hint && get_pageblock_skip(page)) { low_pfn = end_pfn; + page = NULL; goto isolate_abort; } valid_page = page; @@ -943,9 +953,8 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, 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)) @@ -971,10 +980,34 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, if (!(cc->gfp_mask & __GFP_FS) && page_mapping(page)) goto isolate_fail; + /* + * Be careful not to clear PageLRU until after we're + * sure the page is not being freed elsewhere -- the + * page release code relies on it. + */ + if (unlikely(!get_page_unless_zero(page))) + goto isolate_fail; + + if (__isolate_lru_page_prepare(page, isolate_mode) != 0) + goto isolate_fail_put; + + /* Try isolate the page */ + 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) { @@ -983,10 +1016,6 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, goto isolate_abort; } - /* Recheck PageLRU and PageCompound under lock */ - if (!PageLRU(page)) - goto isolate_fail; - /* * Page become compound since the non-locked check, * and it's on LRU. It can only be a THP so the order @@ -994,15 +1023,11 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, */ if (unlikely(PageCompound(page) && !cc->alloc_contig)) { low_pfn += compound_nr(page) - 1; - goto isolate_fail; + SetPageLRU(page); + goto isolate_fail_put; } - } - - lruvec = mem_cgroup_page_lruvec(page, pgdat); - - /* Try isolate the page */ - if (__isolate_lru_page(page, isolate_mode) != 0) - goto isolate_fail; + } else + rcu_read_unlock(); /* The whole page is taken off the LRU; skip the tail pages. */ if (PageCompound(page)) @@ -1032,6 +1057,15 @@ isolate_success: } continue; + +isolate_fail_put: + /* Avoid potential deadlock in freeing page under lru_lock */ + if (locked) { + unlock_page_lruvec_irqrestore(locked, flags); + locked = NULL; + } + put_page(page); + isolate_fail: if (!skip_on_failure) continue; @@ -1043,8 +1077,8 @@ isolate_fail: */ 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; @@ -1068,9 +1102,15 @@ isolate_fail: if (unlikely(low_pfn > end_pfn)) low_pfn = end_pfn; + page = NULL; + isolate_abort: if (locked) - spin_unlock_irqrestore(&pgdat->lru_lock, flags); + unlock_page_lruvec_irqrestore(locked, flags); + if (page) { + SetPageLRU(page); + put_page(page); + } /* * Updated the cached scanner pfn once the pageblock has been scanned diff --git a/mm/filemap.c b/mm/filemap.c index 39bb88140680..c178022d7893 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -102,8 +102,8 @@ * ->swap_lock (try_to_unmap_one) * ->private_lock (try_to_unmap_one) * ->i_pages lock (try_to_unmap_one) - * ->pgdat->lru_lock (follow_page->mark_page_accessed) - * ->pgdat->lru_lock (check_pte_range->isolate_lru_page) + * ->lruvec->lru_lock (follow_page->mark_page_accessed) + * ->lruvec->lru_lock (check_pte_range->isolate_lru_page) * ->private_lock (page_remove_rmap->set_page_dirty) * ->i_pages lock (page_remove_rmap->set_page_dirty) * bdi.wb->list_lock (page_remove_rmap->set_page_dirty) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index e425bbf6711a..1efe2b5ad59a 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2359,6 +2359,27 @@ static void remap_page(struct page *page, unsigned int nr) } } +static void lru_add_page_tail(struct page *head, struct page *tail, + struct lruvec *lruvec, struct list_head *list) +{ + 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->lru_lock); + + if (list) { + /* page reclaim is reclaiming a huge page */ + VM_WARN_ON(PageLRU(head)); + get_page(tail); + list_add_tail(&tail->lru, list); + } else { + /* head is still on lru (and we have it frozen) */ + VM_WARN_ON(!PageLRU(head)); + SetPageLRU(tail); + list_add_tail(&tail->lru, &head->lru); + } +} + static void __split_huge_page_tail(struct page *head, int tail, struct lruvec *lruvec, struct list_head *list) { @@ -2425,18 +2446,15 @@ static void __split_huge_page_tail(struct page *head, int tail, } static void __split_huge_page(struct page *page, struct list_head *list, - pgoff_t end, unsigned long flags) + 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; unsigned int nr = thp_nr_pages(head); int i; - lruvec = mem_cgroup_page_lruvec(head, pgdat); - /* complete memcg works before add pages to LRU */ mem_cgroup_split_huge_fixup(head); @@ -2448,6 +2466,9 @@ static void __split_huge_page(struct page *page, struct list_head *list, xa_lock(&swap_cache->i_pages); } + /* 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); /* Some pages can be beyond i_size: drop them from page cache */ @@ -2467,6 +2488,8 @@ static void __split_huge_page(struct page *page, struct list_head *list, } ClearPageCompound(head); + unlock_page_lruvec(lruvec); + /* Caller disabled irqs, so they are still disabled here */ split_page_owner(head, nr); @@ -2484,8 +2507,7 @@ static void __split_huge_page(struct page *page, struct list_head *list, page_ref_add(head, 2); xa_unlock(&head->mapping->i_pages); } - - spin_unlock_irqrestore(&pgdat->lru_lock, flags); + local_irq_enable(); remap_page(head, nr); @@ -2631,12 +2653,10 @@ bool can_split_huge_page(struct page *page, int *pextra_pins) int split_huge_page_to_list(struct page *page, struct list_head *list) { struct page *head = compound_head(page); - struct pglist_data *pgdata = NODE_DATA(page_to_nid(head)); struct deferred_split *ds_queue = get_deferred_split_queue(head); struct anon_vma *anon_vma = NULL; struct address_space *mapping = NULL; int count, mapcount, extra_pins, ret; - unsigned long flags; pgoff_t end; VM_BUG_ON_PAGE(is_huge_zero_page(head), head); @@ -2697,9 +2717,8 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) unmap_page(head); VM_BUG_ON_PAGE(compound_mapcount(head), head); - /* prevent PageLRU to go away from under us, and freeze lru stats */ - spin_lock_irqsave(&pgdata->lru_lock, flags); - + /* block interrupt reentry in xa_lock and spinlock */ + local_irq_disable(); if (mapping) { XA_STATE(xas, &mapping->i_pages, page_index(head)); @@ -2729,7 +2748,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) __dec_lruvec_page_state(head, NR_FILE_THPS); } - __split_huge_page(page, list, end, flags); + __split_huge_page(page, list, end); ret = 0; } else { if (IS_ENABLED(CONFIG_DEBUG_VM) && mapcount) { @@ -2743,7 +2762,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) spin_unlock(&ds_queue->split_queue_lock); fail: if (mapping) xa_unlock(&mapping->i_pages); - spin_unlock_irqrestore(&pgdata->lru_lock, flags); + local_irq_enable(); remap_page(head, thp_nr_pages(head)); ret = -EBUSY; } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 9c5b14fe360e..e3c7ca7dc174 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -20,6 +20,9 @@ * Lockless page tracking & accounting * Unified hierarchy configuration model * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner + * + * Per memcg lru locking + * Copyright (C) 2020 Alibaba, Inc, Alex Shi */ #include <linux/page_counter.h> @@ -1322,6 +1325,23 @@ 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) +{ + struct mem_cgroup *memcg; + + if (mem_cgroup_disabled()) + return; + + memcg = page_memcg(page); + + if (!memcg) + VM_BUG_ON_PAGE(lruvec_memcg(lruvec) != root_mem_cgroup, page); + else + VM_BUG_ON_PAGE(lruvec_memcg(lruvec) != memcg, page); +} +#endif + /** * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page * @page: the page @@ -1363,6 +1383,60 @@ out: } /** + * lock_page_lruvec - lock and return lruvec for a given page. + * @page: the page + * + * This series functions should be used in either conditions: + * PageLRU is cleared or unset + * or page->_refcount is zero + * or page is locked. + */ +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 * @lru: index of lru list the page is sitting on @@ -2142,6 +2216,12 @@ again: if (unlikely(!memcg)) return NULL; +#ifdef CONFIG_PROVE_LOCKING + local_irq_save(flags); + might_lock(&memcg->move_lock); + local_irq_restore(flags); +#endif + if (atomic_read(&memcg->moving_account) <= 0) return memcg; @@ -3263,10 +3343,8 @@ 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_memcg(head) 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 884b1216da6a..55b3b3672977 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -106,26 +106,6 @@ void mlock_vma_page(struct page *page) } /* - * Isolate a page from LRU with optional get_page() pin. - * Assumes lru_lock already held and page already pinned. - */ -static bool __munlock_isolate_lru_page(struct page *page, bool getpage) -{ - if (PageLRU(page)) { - struct lruvec *lruvec; - - lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page)); - if (getpage) - get_page(page); - ClearPageLRU(page); - del_page_from_lru_list(page, lruvec, page_lru(page)); - return true; - } - - return false; -} - -/* * Finish munlock after successful page isolation * * Page must be locked. This is a wrapper for try_to_munlock() @@ -187,40 +167,24 @@ static void __munlock_isolation_failed(struct page *page) unsigned int munlock_vma_page(struct page *page) { int nr_pages; - pg_data_t *pgdat = page_pgdat(page); /* For try_to_munlock() and to serialize with page migration */ BUG_ON(!PageLocked(page)); - VM_BUG_ON_PAGE(PageTail(page), page); |