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mm/huge_memory.c
63.2 KB
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/* * Copyright (C) 2009 Red Hat, Inc. * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. */ #include <linux/mm.h> #include <linux/sched.h> #include <linux/highmem.h> #include <linux/hugetlb.h> #include <linux/mmu_notifier.h> #include <linux/rmap.h> #include <linux/swap.h> |
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#include <linux/mm_inline.h> #include <linux/kthread.h> #include <linux/khugepaged.h> |
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#include <linux/freezer.h> |
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#include <linux/mman.h> |
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#include <asm/tlb.h> #include <asm/pgalloc.h> #include "internal.h" |
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/* * By default transparent hugepage support is enabled for all mappings * and khugepaged scans all mappings. Defrag is only invoked by * khugepaged hugepage allocations and by page faults inside * MADV_HUGEPAGE regions to avoid the risk of slowing down short lived * allocations. */ |
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unsigned long transparent_hugepage_flags __read_mostly = |
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS |
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(1<<TRANSPARENT_HUGEPAGE_FLAG)| |
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#endif #ifdef CONFIG_TRANSPARENT_HUGEPAGE_MADVISE (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)| #endif |
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(1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)| |
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(1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG); /* default scan 8*512 pte (or vmas) every 30 second */ static unsigned int khugepaged_pages_to_scan __read_mostly = HPAGE_PMD_NR*8; static unsigned int khugepaged_pages_collapsed; static unsigned int khugepaged_full_scans; static unsigned int khugepaged_scan_sleep_millisecs __read_mostly = 10000; /* during fragmentation poll the hugepage allocator once every minute */ static unsigned int khugepaged_alloc_sleep_millisecs __read_mostly = 60000; static struct task_struct *khugepaged_thread __read_mostly; static DEFINE_MUTEX(khugepaged_mutex); static DEFINE_SPINLOCK(khugepaged_mm_lock); static DECLARE_WAIT_QUEUE_HEAD(khugepaged_wait); /* * default collapse hugepages if there is at least one pte mapped like * it would have happened if the vma was large enough during page * fault. */ static unsigned int khugepaged_max_ptes_none __read_mostly = HPAGE_PMD_NR-1; static int khugepaged(void *none); static int mm_slots_hash_init(void); static int khugepaged_slab_init(void); static void khugepaged_slab_free(void); #define MM_SLOTS_HASH_HEADS 1024 static struct hlist_head *mm_slots_hash __read_mostly; static struct kmem_cache *mm_slot_cache __read_mostly; /** * struct mm_slot - hash lookup from mm to mm_slot * @hash: hash collision list * @mm_node: khugepaged scan list headed in khugepaged_scan.mm_head * @mm: the mm that this information is valid for */ struct mm_slot { struct hlist_node hash; struct list_head mm_node; struct mm_struct *mm; }; /** * struct khugepaged_scan - cursor for scanning * @mm_head: the head of the mm list to scan * @mm_slot: the current mm_slot we are scanning * @address: the next address inside that to be scanned * * There is only the one khugepaged_scan instance of this cursor structure. */ struct khugepaged_scan { struct list_head mm_head; struct mm_slot *mm_slot; unsigned long address; |
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}; static struct khugepaged_scan khugepaged_scan = { |
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.mm_head = LIST_HEAD_INIT(khugepaged_scan.mm_head), }; |
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static int set_recommended_min_free_kbytes(void) { struct zone *zone; int nr_zones = 0; unsigned long recommended_min; extern int min_free_kbytes; if (!test_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags) && !test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags)) return 0; for_each_populated_zone(zone) nr_zones++; /* Make sure at least 2 hugepages are free for MIGRATE_RESERVE */ recommended_min = pageblock_nr_pages * nr_zones * 2; /* * Make sure that on average at least two pageblocks are almost free * of another type, one for a migratetype to fall back to and a * second to avoid subsequent fallbacks of other types There are 3 * MIGRATE_TYPES we care about. */ recommended_min += pageblock_nr_pages * nr_zones * MIGRATE_PCPTYPES * MIGRATE_PCPTYPES; /* don't ever allow to reserve more than 5% of the lowmem */ recommended_min = min(recommended_min, (unsigned long) nr_free_buffer_pages() / 20); recommended_min <<= (PAGE_SHIFT-10); if (recommended_min > min_free_kbytes) min_free_kbytes = recommended_min; setup_per_zone_wmarks(); return 0; } late_initcall(set_recommended_min_free_kbytes); |
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static int start_khugepaged(void) { int err = 0; if (khugepaged_enabled()) { int wakeup; if (unlikely(!mm_slot_cache || !mm_slots_hash)) { err = -ENOMEM; goto out; } mutex_lock(&khugepaged_mutex); if (!khugepaged_thread) khugepaged_thread = kthread_run(khugepaged, NULL, "khugepaged"); if (unlikely(IS_ERR(khugepaged_thread))) { printk(KERN_ERR "khugepaged: kthread_run(khugepaged) failed "); err = PTR_ERR(khugepaged_thread); khugepaged_thread = NULL; } wakeup = !list_empty(&khugepaged_scan.mm_head); mutex_unlock(&khugepaged_mutex); if (wakeup) wake_up_interruptible(&khugepaged_wait); |
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set_recommended_min_free_kbytes(); |
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} else /* wakeup to exit */ wake_up_interruptible(&khugepaged_wait); out: return err; } |
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#ifdef CONFIG_SYSFS |
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|
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static ssize_t double_flag_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf, enum transparent_hugepage_flag enabled, enum transparent_hugepage_flag req_madv) { if (test_bit(enabled, &transparent_hugepage_flags)) { VM_BUG_ON(test_bit(req_madv, &transparent_hugepage_flags)); return sprintf(buf, "[always] madvise never "); } else if (test_bit(req_madv, &transparent_hugepage_flags)) return sprintf(buf, "always [madvise] never "); else return sprintf(buf, "always madvise [never] "); } static ssize_t double_flag_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count, enum transparent_hugepage_flag enabled, enum transparent_hugepage_flag req_madv) { if (!memcmp("always", buf, min(sizeof("always")-1, count))) { set_bit(enabled, &transparent_hugepage_flags); clear_bit(req_madv, &transparent_hugepage_flags); } else if (!memcmp("madvise", buf, min(sizeof("madvise")-1, count))) { clear_bit(enabled, &transparent_hugepage_flags); set_bit(req_madv, &transparent_hugepage_flags); } else if (!memcmp("never", buf, min(sizeof("never")-1, count))) { clear_bit(enabled, &transparent_hugepage_flags); clear_bit(req_madv, &transparent_hugepage_flags); } else return -EINVAL; return count; } static ssize_t enabled_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return double_flag_show(kobj, attr, buf, TRANSPARENT_HUGEPAGE_FLAG, TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG); } static ssize_t enabled_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { |
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ssize_t ret; ret = double_flag_store(kobj, attr, buf, count, TRANSPARENT_HUGEPAGE_FLAG, TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG); if (ret > 0) { int err = start_khugepaged(); if (err) ret = err; } |
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if (ret > 0 && (test_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags) || test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags))) set_recommended_min_free_kbytes(); |
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return ret; |
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} static struct kobj_attribute enabled_attr = __ATTR(enabled, 0644, enabled_show, enabled_store); static ssize_t single_flag_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf, enum transparent_hugepage_flag flag) { |
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return sprintf(buf, "%d ", !!test_bit(flag, &transparent_hugepage_flags)); |
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} |
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|
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static ssize_t single_flag_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count, enum transparent_hugepage_flag flag) { |
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unsigned long value; int ret; ret = kstrtoul(buf, 10, &value); if (ret < 0) return ret; if (value > 1) return -EINVAL; if (value) |
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set_bit(flag, &transparent_hugepage_flags); |
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else |
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clear_bit(flag, &transparent_hugepage_flags); |
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return count; } /* * Currently defrag only disables __GFP_NOWAIT for allocation. A blind * __GFP_REPEAT is too aggressive, it's never worth swapping tons of * memory just to allocate one more hugepage. */ static ssize_t defrag_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return double_flag_show(kobj, attr, buf, TRANSPARENT_HUGEPAGE_DEFRAG_FLAG, TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG); } static ssize_t defrag_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { return double_flag_store(kobj, attr, buf, count, TRANSPARENT_HUGEPAGE_DEFRAG_FLAG, TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG); } static struct kobj_attribute defrag_attr = __ATTR(defrag, 0644, defrag_show, defrag_store); #ifdef CONFIG_DEBUG_VM static ssize_t debug_cow_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return single_flag_show(kobj, attr, buf, TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG); } static ssize_t debug_cow_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { return single_flag_store(kobj, attr, buf, count, TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG); } static struct kobj_attribute debug_cow_attr = __ATTR(debug_cow, 0644, debug_cow_show, debug_cow_store); #endif /* CONFIG_DEBUG_VM */ static struct attribute *hugepage_attr[] = { &enabled_attr.attr, &defrag_attr.attr, #ifdef CONFIG_DEBUG_VM &debug_cow_attr.attr, #endif NULL, }; static struct attribute_group hugepage_attr_group = { .attrs = hugepage_attr, |
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}; static ssize_t scan_sleep_millisecs_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%u ", khugepaged_scan_sleep_millisecs); } static ssize_t scan_sleep_millisecs_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { unsigned long msecs; int err; err = strict_strtoul(buf, 10, &msecs); if (err || msecs > UINT_MAX) return -EINVAL; khugepaged_scan_sleep_millisecs = msecs; wake_up_interruptible(&khugepaged_wait); return count; } static struct kobj_attribute scan_sleep_millisecs_attr = __ATTR(scan_sleep_millisecs, 0644, scan_sleep_millisecs_show, scan_sleep_millisecs_store); static ssize_t alloc_sleep_millisecs_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%u ", khugepaged_alloc_sleep_millisecs); } static ssize_t alloc_sleep_millisecs_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { unsigned long msecs; int err; err = strict_strtoul(buf, 10, &msecs); if (err || msecs > UINT_MAX) return -EINVAL; khugepaged_alloc_sleep_millisecs = msecs; wake_up_interruptible(&khugepaged_wait); return count; } static struct kobj_attribute alloc_sleep_millisecs_attr = __ATTR(alloc_sleep_millisecs, 0644, alloc_sleep_millisecs_show, alloc_sleep_millisecs_store); static ssize_t pages_to_scan_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%u ", khugepaged_pages_to_scan); } static ssize_t pages_to_scan_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { int err; unsigned long pages; err = strict_strtoul(buf, 10, &pages); if (err || !pages || pages > UINT_MAX) return -EINVAL; khugepaged_pages_to_scan = pages; return count; } static struct kobj_attribute pages_to_scan_attr = __ATTR(pages_to_scan, 0644, pages_to_scan_show, pages_to_scan_store); static ssize_t pages_collapsed_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%u ", khugepaged_pages_collapsed); } static struct kobj_attribute pages_collapsed_attr = __ATTR_RO(pages_collapsed); static ssize_t full_scans_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%u ", khugepaged_full_scans); } static struct kobj_attribute full_scans_attr = __ATTR_RO(full_scans); static ssize_t khugepaged_defrag_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return single_flag_show(kobj, attr, buf, TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG); } static ssize_t khugepaged_defrag_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { return single_flag_store(kobj, attr, buf, count, TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG); } static struct kobj_attribute khugepaged_defrag_attr = __ATTR(defrag, 0644, khugepaged_defrag_show, khugepaged_defrag_store); /* * max_ptes_none controls if khugepaged should collapse hugepages over * any unmapped ptes in turn potentially increasing the memory * footprint of the vmas. When max_ptes_none is 0 khugepaged will not * reduce the available free memory in the system as it * runs. Increasing max_ptes_none will instead potentially reduce the * free memory in the system during the khugepaged scan. */ static ssize_t khugepaged_max_ptes_none_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%u ", khugepaged_max_ptes_none); } static ssize_t khugepaged_max_ptes_none_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { int err; unsigned long max_ptes_none; err = strict_strtoul(buf, 10, &max_ptes_none); if (err || max_ptes_none > HPAGE_PMD_NR-1) return -EINVAL; khugepaged_max_ptes_none = max_ptes_none; return count; } static struct kobj_attribute khugepaged_max_ptes_none_attr = __ATTR(max_ptes_none, 0644, khugepaged_max_ptes_none_show, khugepaged_max_ptes_none_store); static struct attribute *khugepaged_attr[] = { &khugepaged_defrag_attr.attr, &khugepaged_max_ptes_none_attr.attr, &pages_to_scan_attr.attr, &pages_collapsed_attr.attr, &full_scans_attr.attr, &scan_sleep_millisecs_attr.attr, &alloc_sleep_millisecs_attr.attr, NULL, }; static struct attribute_group khugepaged_attr_group = { .attrs = khugepaged_attr, .name = "khugepaged", |
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}; #endif /* CONFIG_SYSFS */ static int __init hugepage_init(void) { |
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int err; |
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#ifdef CONFIG_SYSFS static struct kobject *hugepage_kobj; |
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#endif |
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|
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err = -EINVAL; if (!has_transparent_hugepage()) { transparent_hugepage_flags = 0; goto out; } #ifdef CONFIG_SYSFS |
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err = -ENOMEM; hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj); if (unlikely(!hugepage_kobj)) { printk(KERN_ERR "hugepage: failed kobject create "); goto out; } err = sysfs_create_group(hugepage_kobj, &hugepage_attr_group); if (err) { printk(KERN_ERR "hugepage: failed register hugeage group "); goto out; } err = sysfs_create_group(hugepage_kobj, &khugepaged_attr_group); if (err) { printk(KERN_ERR "hugepage: failed register hugeage group "); goto out; } |
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#endif |
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err = khugepaged_slab_init(); if (err) goto out; err = mm_slots_hash_init(); if (err) { khugepaged_slab_free(); goto out; } |
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/* * By default disable transparent hugepages on smaller systems, * where the extra memory used could hurt more than TLB overhead * is likely to save. The admin can still enable it through /sys. */ if (totalram_pages < (512 << (20 - PAGE_SHIFT))) transparent_hugepage_flags = 0; |
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start_khugepaged(); |
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set_recommended_min_free_kbytes(); |
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out: return err; |
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} module_init(hugepage_init) static int __init setup_transparent_hugepage(char *str) { int ret = 0; if (!str) goto out; if (!strcmp(str, "always")) { set_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); ret = 1; } else if (!strcmp(str, "madvise")) { clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); ret = 1; } else if (!strcmp(str, "never")) { clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); ret = 1; } out: if (!ret) printk(KERN_WARNING "transparent_hugepage= cannot parse, ignored "); return ret; } __setup("transparent_hugepage=", setup_transparent_hugepage); static void prepare_pmd_huge_pte(pgtable_t pgtable, struct mm_struct *mm) { assert_spin_locked(&mm->page_table_lock); /* FIFO */ if (!mm->pmd_huge_pte) INIT_LIST_HEAD(&pgtable->lru); else list_add(&pgtable->lru, &mm->pmd_huge_pte->lru); mm->pmd_huge_pte = pgtable; } static inline pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) { if (likely(vma->vm_flags & VM_WRITE)) pmd = pmd_mkwrite(pmd); return pmd; } static int __do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long haddr, pmd_t *pmd, struct page *page) { int ret = 0; pgtable_t pgtable; VM_BUG_ON(!PageCompound(page)); pgtable = pte_alloc_one(mm, haddr); if (unlikely(!pgtable)) { |
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mem_cgroup_uncharge_page(page); |
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put_page(page); return VM_FAULT_OOM; } clear_huge_page(page, haddr, HPAGE_PMD_NR); __SetPageUptodate(page); spin_lock(&mm->page_table_lock); if (unlikely(!pmd_none(*pmd))) { spin_unlock(&mm->page_table_lock); |
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mem_cgroup_uncharge_page(page); |
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put_page(page); pte_free(mm, pgtable); } else { pmd_t entry; entry = mk_pmd(page, vma->vm_page_prot); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); entry = pmd_mkhuge(entry); /* * The spinlocking to take the lru_lock inside * page_add_new_anon_rmap() acts as a full memory * barrier to be sure clear_huge_page writes become * visible after the set_pmd_at() write. */ page_add_new_anon_rmap(page, vma, haddr); set_pmd_at(mm, haddr, pmd, entry); prepare_pmd_huge_pte(pgtable, mm); add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR); spin_unlock(&mm->page_table_lock); } return ret; } |
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static inline gfp_t alloc_hugepage_gfpmask(int defrag, gfp_t extra_gfp) |
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{ |
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return (GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT)) | extra_gfp; |
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} static inline struct page *alloc_hugepage_vma(int defrag, struct vm_area_struct *vma, |
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unsigned long haddr, int nd, gfp_t extra_gfp) |
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{ |
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return alloc_pages_vma(alloc_hugepage_gfpmask(defrag, extra_gfp), |
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HPAGE_PMD_ORDER, vma, haddr, nd); |
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} #ifndef CONFIG_NUMA |
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static inline struct page *alloc_hugepage(int defrag) { |
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return alloc_pages(alloc_hugepage_gfpmask(defrag, 0), |
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HPAGE_PMD_ORDER); } |
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#endif |
71e3aac07 thp: transparent ... |
677 678 679 680 681 682 683 684 685 686 687 688 |
int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pmd_t *pmd, unsigned int flags) { struct page *page; unsigned long haddr = address & HPAGE_PMD_MASK; pte_t *pte; if (haddr >= vma->vm_start && haddr + HPAGE_PMD_SIZE <= vma->vm_end) { if (unlikely(anon_vma_prepare(vma))) return VM_FAULT_OOM; |
ba76149f4 thp: khugepaged |
689 690 |
if (unlikely(khugepaged_enter(vma))) return VM_FAULT_OOM; |
0bbbc0b33 thp: add numa awa... |
691 |
page = alloc_hugepage_vma(transparent_hugepage_defrag(vma), |
cc5d462f7 mm: use __GFP_OTH... |
692 |
vma, haddr, numa_node_id(), 0); |
81ab4201f mm: add VM counte... |
693 694 |
if (unlikely(!page)) { count_vm_event(THP_FAULT_FALLBACK); |
71e3aac07 thp: transparent ... |
695 |
goto out; |
81ab4201f mm: add VM counte... |
696 697 |
} count_vm_event(THP_FAULT_ALLOC); |
b9bbfbe30 thp: memcg huge m... |
698 699 700 701 |
if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) { put_page(page); goto out; } |
71e3aac07 thp: transparent ... |
702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 |
return __do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page); } out: /* * Use __pte_alloc instead of pte_alloc_map, because we can't * run pte_offset_map on the pmd, if an huge pmd could * materialize from under us from a different thread. */ if (unlikely(__pte_alloc(mm, vma, pmd, address))) return VM_FAULT_OOM; /* if an huge pmd materialized from under us just retry later */ if (unlikely(pmd_trans_huge(*pmd))) return 0; /* * A regular pmd is established and it can't morph into a huge pmd * from under us anymore at this point because we hold the mmap_sem * read mode and khugepaged takes it in write mode. So now it's * safe to run pte_offset_map(). */ pte = pte_offset_map(pmd, address); return handle_pte_fault(mm, vma, address, pte, pmd, flags); } int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr, struct vm_area_struct *vma) { struct page *src_page; pmd_t pmd; pgtable_t pgtable; int ret; ret = -ENOMEM; pgtable = pte_alloc_one(dst_mm, addr); if (unlikely(!pgtable)) goto out; spin_lock(&dst_mm->page_table_lock); spin_lock_nested(&src_mm->page_table_lock, SINGLE_DEPTH_NESTING); ret = -EAGAIN; pmd = *src_pmd; if (unlikely(!pmd_trans_huge(pmd))) { pte_free(dst_mm, pgtable); goto out_unlock; } if (unlikely(pmd_trans_splitting(pmd))) { /* split huge page running from under us */ spin_unlock(&src_mm->page_table_lock); spin_unlock(&dst_mm->page_table_lock); pte_free(dst_mm, pgtable); wait_split_huge_page(vma->anon_vma, src_pmd); /* src_vma */ goto out; } src_page = pmd_page(pmd); VM_BUG_ON(!PageHead(src_page)); get_page(src_page); page_dup_rmap(src_page); add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR); pmdp_set_wrprotect(src_mm, addr, src_pmd); pmd = pmd_mkold(pmd_wrprotect(pmd)); set_pmd_at(dst_mm, addr, dst_pmd, pmd); prepare_pmd_huge_pte(pgtable, dst_mm); ret = 0; out_unlock: spin_unlock(&src_mm->page_table_lock); spin_unlock(&dst_mm->page_table_lock); out: return ret; } /* no "address" argument so destroys page coloring of some arch */ pgtable_t get_pmd_huge_pte(struct mm_struct *mm) { pgtable_t pgtable; assert_spin_locked(&mm->page_table_lock); /* FIFO */ pgtable = mm->pmd_huge_pte; if (list_empty(&pgtable->lru)) mm->pmd_huge_pte = NULL; else { mm->pmd_huge_pte = list_entry(pgtable->lru.next, struct page, lru); list_del(&pgtable->lru); } return pgtable; } static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pmd_t *pmd, pmd_t orig_pmd, struct page *page, unsigned long haddr) { pgtable_t pgtable; pmd_t _pmd; int ret = 0, i; struct page **pages; pages = kmalloc(sizeof(struct page *) * HPAGE_PMD_NR, GFP_KERNEL); if (unlikely(!pages)) { ret |= VM_FAULT_OOM; goto out; } for (i = 0; i < HPAGE_PMD_NR; i++) { |
cc5d462f7 mm: use __GFP_OTH... |
816 817 |
pages[i] = alloc_page_vma_node(GFP_HIGHUSER_MOVABLE | __GFP_OTHER_NODE, |
19ee151e1 mm: preserve orig... |
818 |
vma, address, page_to_nid(page)); |
b9bbfbe30 thp: memcg huge m... |
819 820 821 822 |
if (unlikely(!pages[i] || mem_cgroup_newpage_charge(pages[i], mm, GFP_KERNEL))) { if (pages[i]) |
71e3aac07 thp: transparent ... |
823 |
put_page(pages[i]); |
b9bbfbe30 thp: memcg huge m... |
824 825 826 827 828 829 |
mem_cgroup_uncharge_start(); while (--i >= 0) { mem_cgroup_uncharge_page(pages[i]); put_page(pages[i]); } mem_cgroup_uncharge_end(); |
71e3aac07 thp: transparent ... |
830 831 832 833 834 835 836 837 |
kfree(pages); ret |= VM_FAULT_OOM; goto out; } } for (i = 0; i < HPAGE_PMD_NR; i++) { copy_user_highpage(pages[i], page + i, |
0089e4853 mm/huge_memory: f... |
838 |
haddr + PAGE_SIZE * i, vma); |
71e3aac07 thp: transparent ... |
839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 |
__SetPageUptodate(pages[i]); cond_resched(); } spin_lock(&mm->page_table_lock); if (unlikely(!pmd_same(*pmd, orig_pmd))) goto out_free_pages; VM_BUG_ON(!PageHead(page)); pmdp_clear_flush_notify(vma, haddr, pmd); /* leave pmd empty until pte is filled */ pgtable = get_pmd_huge_pte(mm); pmd_populate(mm, &_pmd, pgtable); for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) { pte_t *pte, entry; entry = mk_pte(pages[i], vma->vm_page_prot); entry = maybe_mkwrite(pte_mkdirty(entry), vma); page_add_new_anon_rmap(pages[i], vma, haddr); pte = pte_offset_map(&_pmd, haddr); VM_BUG_ON(!pte_none(*pte)); set_pte_at(mm, haddr, pte, entry); pte_unmap(pte); } kfree(pages); mm->nr_ptes++; smp_wmb(); /* make pte visible before pmd */ pmd_populate(mm, pmd, pgtable); page_remove_rmap(page); spin_unlock(&mm->page_table_lock); ret |= VM_FAULT_WRITE; put_page(page); out: return ret; out_free_pages: spin_unlock(&mm->page_table_lock); |
b9bbfbe30 thp: memcg huge m... |
880 881 882 |
mem_cgroup_uncharge_start(); for (i = 0; i < HPAGE_PMD_NR; i++) { mem_cgroup_uncharge_page(pages[i]); |
71e3aac07 thp: transparent ... |
883 |
put_page(pages[i]); |
b9bbfbe30 thp: memcg huge m... |
884 885 |
} mem_cgroup_uncharge_end(); |
71e3aac07 thp: transparent ... |
886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 |
kfree(pages); goto out; } int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pmd_t *pmd, pmd_t orig_pmd) { int ret = 0; struct page *page, *new_page; unsigned long haddr; VM_BUG_ON(!vma->anon_vma); spin_lock(&mm->page_table_lock); if (unlikely(!pmd_same(*pmd, orig_pmd))) goto out_unlock; page = pmd_page(orig_pmd); VM_BUG_ON(!PageCompound(page) || !PageHead(page)); haddr = address & HPAGE_PMD_MASK; if (page_mapcount(page) == 1) { pmd_t entry; entry = pmd_mkyoung(orig_pmd); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); if (pmdp_set_access_flags(vma, haddr, pmd, entry, 1)) update_mmu_cache(vma, address, entry); ret |= VM_FAULT_WRITE; goto out_unlock; } get_page(page); spin_unlock(&mm->page_table_lock); if (transparent_hugepage_enabled(vma) && !transparent_hugepage_debug_cow()) |
0bbbc0b33 thp: add numa awa... |
919 |
new_page = alloc_hugepage_vma(transparent_hugepage_defrag(vma), |
cc5d462f7 mm: use __GFP_OTH... |
920 |
vma, haddr, numa_node_id(), 0); |
71e3aac07 thp: transparent ... |
921 922 923 924 |
else new_page = NULL; if (unlikely(!new_page)) { |
81ab4201f mm: add VM counte... |
925 |
count_vm_event(THP_FAULT_FALLBACK); |
71e3aac07 thp: transparent ... |
926 927 928 929 930 |
ret = do_huge_pmd_wp_page_fallback(mm, vma, address, pmd, orig_pmd, page, haddr); put_page(page); goto out; } |
81ab4201f mm: add VM counte... |
931 |
count_vm_event(THP_FAULT_ALLOC); |
71e3aac07 thp: transparent ... |
932 |
|
b9bbfbe30 thp: memcg huge m... |
933 934 935 936 937 938 |
if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) { put_page(new_page); put_page(page); ret |= VM_FAULT_OOM; goto out; } |
71e3aac07 thp: transparent ... |
939 940 941 942 943 |
copy_user_huge_page(new_page, page, haddr, vma, HPAGE_PMD_NR); __SetPageUptodate(new_page); spin_lock(&mm->page_table_lock); put_page(page); |
b9bbfbe30 thp: memcg huge m... |
944 945 |
if (unlikely(!pmd_same(*pmd, orig_pmd))) { mem_cgroup_uncharge_page(new_page); |
71e3aac07 thp: transparent ... |
946 |
put_page(new_page); |
b9bbfbe30 thp: memcg huge m... |
947 |
} else { |
71e3aac07 thp: transparent ... |
948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 |
pmd_t entry; VM_BUG_ON(!PageHead(page)); entry = mk_pmd(new_page, vma->vm_page_prot); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); entry = pmd_mkhuge(entry); pmdp_clear_flush_notify(vma, haddr, pmd); page_add_new_anon_rmap(new_page, vma, haddr); set_pmd_at(mm, haddr, pmd, entry); update_mmu_cache(vma, address, entry); page_remove_rmap(page); put_page(page); ret |= VM_FAULT_WRITE; } out_unlock: spin_unlock(&mm->page_table_lock); out: return ret; } struct page *follow_trans_huge_pmd(struct mm_struct *mm, unsigned long addr, pmd_t *pmd, unsigned int flags) { struct page *page = NULL; assert_spin_locked(&mm->page_table_lock); if (flags & FOLL_WRITE && !pmd_write(*pmd)) goto out; page = pmd_page(*pmd); VM_BUG_ON(!PageHead(page)); if (flags & FOLL_TOUCH) { pmd_t _pmd; /* * We should set the dirty bit only for FOLL_WRITE but * for now the dirty bit in the pmd is meaningless. * And if the dirty bit will become meaningful and * we'll only set it with FOLL_WRITE, an atomic * set_bit will be required on the pmd to set the * young bit, instead of the current set_pmd_at. */ _pmd = pmd_mkyoung(pmd_mkdirty(*pmd)); set_pmd_at(mm, addr & HPAGE_PMD_MASK, pmd, _pmd); } page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT; VM_BUG_ON(!PageCompound(page)); if (flags & FOLL_GET) |
70b50f94f mm: thp: tail pag... |
997 |
get_page_foll(page); |
71e3aac07 thp: transparent ... |
998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 |
out: return page; } int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, pmd_t *pmd) { int ret = 0; spin_lock(&tlb->mm->page_table_lock); if (likely(pmd_trans_huge(*pmd))) { if (unlikely(pmd_trans_splitting(*pmd))) { spin_unlock(&tlb->mm->page_table_lock); wait_split_huge_page(vma->anon_vma, pmd); } else { struct page *page; pgtable_t pgtable; pgtable = get_pmd_huge_pte(tlb->mm); page = pmd_page(*pmd); pmd_clear(pmd); page_remove_rmap(page); VM_BUG_ON(page_mapcount(page) < 0); add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); VM_BUG_ON(!PageHead(page)); spin_unlock(&tlb->mm->page_table_lock); tlb_remove_page(tlb, page); pte_free(tlb->mm, pgtable); ret = 1; } } else spin_unlock(&tlb->mm->page_table_lock); return ret; } |
0ca1634d4 thp: mincore tran... |
1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 |
int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, unsigned char *vec) { int ret = 0; spin_lock(&vma->vm_mm->page_table_lock); if (likely(pmd_trans_huge(*pmd))) { ret = !pmd_trans_splitting(*pmd); spin_unlock(&vma->vm_mm->page_table_lock); if (unlikely(!ret)) wait_split_huge_page(vma->anon_vma, pmd); else { /* * All logical pages in the range are present * if backed by a huge page. */ memset(vec, 1, (end - addr) >> PAGE_SHIFT); } } else spin_unlock(&vma->vm_mm->page_table_lock); return ret; } |
37a1c49a9 thp: mremap suppo... |
1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 |
int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma, unsigned long old_addr, unsigned long new_addr, unsigned long old_end, pmd_t *old_pmd, pmd_t *new_pmd) { int ret = 0; pmd_t pmd; struct mm_struct *mm = vma->vm_mm; if ((old_addr & ~HPAGE_PMD_MASK) || (new_addr & ~HPAGE_PMD_MASK) || old_end - old_addr < HPAGE_PMD_SIZE || (new_vma->vm_flags & VM_NOHUGEPAGE)) goto out; /* * The destination pmd shouldn't be established, free_pgtables() * should have release it. */ if (WARN_ON(!pmd_none(*new_pmd))) { VM_BUG_ON(pmd_trans_huge(*new_pmd)); goto out; } spin_lock(&mm->page_table_lock); if (likely(pmd_trans_huge(*old_pmd))) { if (pmd_trans_splitting(*old_pmd)) { spin_unlock(&mm->page_table_lock); wait_split_huge_page(vma->anon_vma, old_pmd); ret = -1; } else { pmd = pmdp_get_and_clear(mm, old_addr, old_pmd); VM_BUG_ON(!pmd_none(*new_pmd)); set_pmd_at(mm, new_addr, new_pmd, pmd); spin_unlock(&mm->page_table_lock); ret = 1; } } else { spin_unlock(&mm->page_table_lock); } out: return ret; } |
cd7548ab3 thp: mprotect: tr... |
1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 |
int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, pgprot_t newprot) { struct mm_struct *mm = vma->vm_mm; int ret = 0; spin_lock(&mm->page_table_lock); if (likely(pmd_trans_huge(*pmd))) { if (unlikely(pmd_trans_splitting(*pmd))) { spin_unlock(&mm->page_table_lock); wait_split_huge_page(vma->anon_vma, pmd); } else { pmd_t entry; entry = pmdp_get_and_clear(mm, addr, pmd); entry = pmd_modify(entry, newprot); set_pmd_at(mm, addr, pmd, entry); spin_unlock(&vma->vm_mm->page_table_lock); flush_tlb_range(vma, addr, addr + HPAGE_PMD_SIZE); ret = 1; } } else spin_unlock(&vma->vm_mm->page_table_lock); return ret; } |
71e3aac07 thp: transparent ... |
1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 |
pmd_t *page_check_address_pmd(struct page *page, struct mm_struct *mm, unsigned long address, enum page_check_address_pmd_flag flag) { pgd_t *pgd; pud_t *pud; pmd_t *pmd, *ret = NULL; if (address & ~HPAGE_PMD_MASK) goto out; pgd = pgd_offset(mm, address); if (!pgd_present(*pgd)) goto out; pud = pud_offset(pgd, address); if (!pud_present(*pud)) goto out; pmd = pmd_offset(pud, address); if (pmd_none(*pmd)) goto out; if (pmd_page(*pmd) != page) goto out; |
94fcc585f thp: avoid breaki... |
1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 |
/* * split_vma() may create temporary aliased mappings. There is * no risk as long as all huge pmd are found and have their * splitting bit set before __split_huge_page_refcount * runs. Finding the same huge pmd more than once during the * same rmap walk is not a problem. */ if (flag == PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG && pmd_trans_splitting(*pmd)) goto out; |
71e3aac07 thp: transparent ... |
1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 |
if (pmd_trans_huge(*pmd)) { VM_BUG_ON(flag == PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG && !pmd_trans_splitting(*pmd)); ret = pmd; } out: return ret; } static int __split_huge_page_splitting(struct page *page, struct vm_area_struct *vma, unsigned long address) { struct mm_struct *mm = vma->vm_mm; pmd_t *pmd; int ret = 0; spin_lock(&mm->page_table_lock); pmd = page_check_address_pmd(page, mm, address, PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG); if (pmd) { /* * We can't temporarily set the pmd to null in order * to split it, the pmd must remain marked huge at all * times or the VM won't take the pmd_trans_huge paths |
2b575eb64 mm: convert anon_... |
1188 |
* and it won't wait on the anon_vma->root->mutex to |
71e3aac07 thp: transparent ... |
1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 |
* serialize against split_huge_page*. */ pmdp_splitting_flush_notify(vma, address, pmd); ret = 1; } spin_unlock(&mm->page_table_lock); return ret; } static void __split_huge_page_refcount(struct page *page) { int i; unsigned long head_index = page->index; struct zone *zone = page_zone(page); |
2c888cfbc thp: fix anon mem... |
1204 |
int zonestat; |
70b50f94f mm: thp: tail pag... |
1205 |
int tail_count = 0; |
71e3aac07 thp: transparent ... |
1206 1207 1208 1209 |
/* prevent PageLRU to go away from under us, and freeze lru stats */ spin_lock_irq(&zone->lru_lock); compound_lock(page); |
e94c8a9cb memcg: make mem_c... |
1210 1211 |
/* complete memcg works before add pages to LRU */ mem_cgroup_split_huge_fixup(page); |
71e3aac07 thp: transparent ... |
1212 1213 1214 |
for (i = 1; i < HPAGE_PMD_NR; i++) { struct page *page_tail = page + i; |
70b50f94f mm: thp: tail pag... |
1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 |
/* tail_page->_mapcount cannot change */ BUG_ON(page_mapcount(page_tail) < 0); tail_count += page_mapcount(page_tail); /* check for overflow */ BUG_ON(tail_count < 0); BUG_ON(atomic_read(&page_tail->_count) != 0); /* * tail_page->_count is zero and not changing from * under us. But get_page_unless_zero() may be running * from under us on the tail_page. If we used * atomic_set() below instead of atomic_add(), we * would then run atomic_set() concurrently with * get_page_unless_zero(), and atomic_set() is * implemented in C not using locked ops. spin_unlock * on x86 sometime uses locked ops because of PPro * errata 66, 92, so unless somebody can guarantee * atomic_set() here would be safe on all archs (and * not only on x86), it's safer to use atomic_add(). */ atomic_add(page_mapcount(page) + page_mapcount(page_tail) + 1, &page_tail->_count); |
71e3aac07 thp: transparent ... |
1236 1237 1238 |
/* after clearing PageTail the gup refcount can be released */ smp_mb(); |
a6d30ddda thp: fix the wron... |
1239 1240 1241 1242 1243 1244 |
/* * retain hwpoison flag of the poisoned tail page: * fix for the unsuitable process killed on Guest Machine(KVM) * by the memory-failure. */ page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP | __PG_HWPOISON; |
71e3aac07 thp: transparent ... |
1245 1246 1247 1248 1249 1250 |
page_tail->flags |= (page->flags & ((1L << PG_referenced) | (1L << PG_swapbacked) | (1L << PG_mlocked) | (1L << PG_uptodate))); page_tail->flags |= (1L << PG_dirty); |
70b50f94f mm: thp: tail pag... |
1251 |
/* clear PageTail before overwriting first_page */ |
71e3aac07 thp: transparent ... |
1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 |
smp_wmb(); /* * __split_huge_page_splitting() already set the * splitting bit in all pmd that could map this * hugepage, that will ensure no CPU can alter the * mapcount on the head page. The mapcount is only * accounted in the head page and it has to be * transferred to all tail pages in the below code. So * for this code to be safe, the split the mapcount * can't change. But that doesn't mean userland can't * keep changing and reading the page contents while * we transfer the mapcount, so the pmd splitting * status is achieved setting a reserved bit in the * pmd, not by clearing the present bit. */ |
71e3aac07 thp: transparent ... |
1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 |
page_tail->_mapcount = page->_mapcount; BUG_ON(page_tail->mapping); page_tail->mapping = page->mapping; page_tail->index = ++head_index; BUG_ON(!PageAnon(page_tail)); BUG_ON(!PageUptodate(page_tail)); BUG_ON(!PageDirty(page_tail)); BUG_ON(!PageSwapBacked(page_tail)); |
ca3e02141 memcg: fix USED b... |
1279 |
|
71e3aac07 thp: transparent ... |
1280 1281 |
lru_add_page_tail(zone, page, page_tail); } |
70b50f94f mm: thp: tail pag... |
1282 1283 |
atomic_sub(tail_count, &page->_count); BUG_ON(atomic_read(&page->_count) <= 0); |
71e3aac07 thp: transparent ... |
1284 |
|
79134171d thp: transparent ... |
1285 1286 |
__dec_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES); __mod_zone_page_state(zone, NR_ANON_PAGES, HPAGE_PMD_NR); |
2c888cfbc thp: fix anon mem... |
1287 1288 1289 1290 1291 1292 1293 1294 |
/* * A hugepage counts for HPAGE_PMD_NR pages on the LRU statistics, * so adjust those appropriately if this page is on the LRU. */ if (PageLRU(page)) { zonestat = NR_LRU_BASE + page_lru(page); __mod_zone_page_state(zone, zonestat, -(HPAGE_PMD_NR-1)); } |
71e3aac07 thp: transparent ... |
1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 |
ClearPageCompound(page); compound_unlock(page); spin_unlock_irq(&zone->lru_lock); for (i = 1; i < HPAGE_PMD_NR; i++) { struct page *page_tail = page + i; BUG_ON(page_count(page_tail) <= 0); /* * Tail pages may be freed if there wasn't any mapping * like if add_to_swap() is running on a lru page that * had its mapping zapped. And freeing these pages * requires taking the lru_lock so we do the put_page * of the tail pages after the split is complete. */ put_page(page_tail); } /* * Only the head page (now become a regular page) is required * to be pinned by the caller. */ BUG_ON(page_count(page) <= 0); } static int __split_huge_page_map(struct page *page, struct vm_area_struct *vma, unsigned long address) { struct mm_struct *mm = vma->vm_mm; pmd_t *pmd, _pmd; int ret = 0, i; pgtable_t pgtable; unsigned long haddr; spin_lock(&mm->page_table_lock); pmd = page_check_address_pmd(page, mm, address, PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG); if (pmd) { pgtable = get_pmd_huge_pte(mm); pmd_populate(mm, &_pmd, pgtable); for (i = 0, haddr = address; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) { pte_t *pte, entry; BUG_ON(PageCompound(page+i)); entry = mk_pte(page + i, vma->vm_page_prot); entry = maybe_mkwrite(pte_mkdirty(entry), vma); if (!pmd_write(*pmd)) entry = pte_wrprotect(entry); else BUG_ON(page_mapcount(page) != 1); if (!pmd_young(*pmd)) entry = pte_mkold(entry); pte = pte_offset_map(&_pmd, haddr); BUG_ON(!pte_none(*pte)); set_pte_at(mm, haddr, pte, entry); pte_unmap(pte); } mm->nr_ptes++; smp_wmb(); /* make pte visible before pmd */ /* * Up to this point the pmd is present and huge and * userland has the whole access to the hugepage * during the split (which happens in place). If we * overwrite the pmd with the not-huge version * pointing to the pte here (which of course we could * if all CPUs were bug free), userland could trigger * a small page size TLB miss on the small sized TLB * while the hugepage TLB entry is still established * in the huge TLB. Some CPU doesn't like that. See * http://support.amd.com/us/Processor_TechDocs/41322.pdf, * Erratum 383 on page 93. Intel should be safe but is * also warns that it's only safe if the permission * and cache attributes of the two entries loaded in * the two TLB is identical (which should be the case * here). But it is generally safer to never allow * small and huge TLB entries for the same virtual * address to be loaded simultaneously. So instead of * doing "pmd_populate(); flush_tlb_range();" we first * mark the current pmd notpresent (atomically because * here the pmd_trans_huge and pmd_trans_splitting * must remain set at all times on the pmd until the * split is complete for this pmd), then we flush the * SMP TLB and finally we write the non-huge version * of the pmd entry with pmd_populate. */ set_pmd_at(mm, address, pmd, pmd_mknotpresent(*pmd)); flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); pmd_populate(mm, pmd, pgtable); ret = 1; } spin_unlock(&mm->page_table_lock); return ret; } |
2b575eb64 mm: convert anon_... |
1391 |
/* must be called with anon_vma->root->mutex hold */ |
71e3aac07 thp: transparent ... |
1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 |
static void __split_huge_page(struct page *page, struct anon_vma *anon_vma) { int mapcount, mapcount2; struct anon_vma_chain *avc; BUG_ON(!PageHead(page)); BUG_ON(PageTail(page)); mapcount = 0; list_for_each_entry(avc, &anon_vma->head, same_anon_vma) { struct vm_area_struct *vma = avc->vma; unsigned long addr = vma_address(page, vma); BUG_ON(is_vma_temporary_stack(vma)); if (addr == -EFAULT) continue; mapcount += __split_huge_page_splitting(page, vma, addr); } |
05759d380 thp: split_huge_p... |
1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 |
/* * It is critical that new vmas are added to the tail of the * anon_vma list. This guarantes that if copy_huge_pmd() runs * and establishes a child pmd before * __split_huge_page_splitting() freezes the parent pmd (so if * we fail to prevent copy_huge_pmd() from running until the * whole __split_huge_page() is complete), we will still see * the newly established pmd of the child later during the * walk, to be able to set it as pmd_trans_splitting too. */ if (mapcount != page_mapcount(page)) printk(KERN_ERR "mapcount %d page_mapcount %d ", mapcount, page_mapcount(page)); |
71e3aac07 thp: transparent ... |
1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 |
BUG_ON(mapcount != page_mapcount(page)); __split_huge_page_refcount(page); mapcount2 = 0; list_for_each_entry(avc, &anon_vma->head, same_anon_vma) { struct vm_area_struct *vma = avc->vma; unsigned long addr = vma_address(page, vma); BUG_ON(is_vma_temporary_stack(vma)); if (addr == -EFAULT) continue; mapcount2 += __split_huge_page_map(page, vma, addr); } |
05759d380 thp: split_huge_p... |
1437 1438 1439 1440 |
if (mapcount != mapcount2) printk(KERN_ERR "mapcount %d mapcount2 %d page_mapcount %d ", mapcount, mapcount2, page_mapcount(page)); |
71e3aac07 thp: transparent ... |
1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 |
BUG_ON(mapcount != mapcount2); } int split_huge_page(struct page *page) { struct anon_vma *anon_vma; int ret = 1; BUG_ON(!PageAnon(page)); anon_vma = page_lock_anon_vma(page); if (!anon_vma) goto out; ret = 0; if (!PageCompound(page)) goto out_unlock; BUG_ON(!PageSwapBacked(page)); __split_huge_page(page, anon_vma); |
81ab4201f mm: add VM counte... |
1459 |
count_vm_event(THP_SPLIT); |
71e3aac07 thp: transparent ... |
1460 1461 1462 1463 1464 1465 1466 |
BUG_ON(PageCompound(page)); out_unlock: page_unlock_anon_vma(anon_vma); out: return ret; } |
78f11a255 mm: thp: fix /dev... |
1467 1468 |
#define VM_NO_THP (VM_SPECIAL|VM_INSERTPAGE|VM_MIXEDMAP|VM_SAO| \ VM_HUGETLB|VM_SHARED|VM_MAYSHARE) |
60ab3244e thp: khugepaged: ... |
1469 1470 |
int hugepage_madvise(struct vm_area_struct *vma, unsigned long *vm_flags, int advice) |
0af4e98b6 thp: madvise(MADV... |
1471 |
{ |
a664b2d85 thp: madvise(MADV... |
1472 1473 1474 1475 1476 |
switch (advice) { case MADV_HUGEPAGE: /* * Be somewhat over-protective like KSM for now! */ |
78f11a255 mm: thp: fix /dev... |
1477 |
if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP)) |
a664b2d85 thp: madvise(MADV... |
1478 1479 1480 |
return -EINVAL; *vm_flags &= ~VM_NOHUGEPAGE; *vm_flags |= VM_HUGEPAGE; |
60ab3244e thp: khugepaged: ... |
1481 1482 1483 1484 1485 1486 1487 |
/* * If the vma become good for khugepaged to scan, * register it here without waiting a page fault that * may not happen any time soon. */ if (unlikely(khugepaged_enter_vma_merge(vma))) return -ENOMEM; |
a664b2d85 thp: madvise(MADV... |
1488 1489 1490 1491 1492 |
break; case MADV_NOHUGEPAGE: /* * Be somewhat over-protective like KSM for now! */ |
78f11a255 mm: thp: fix /dev... |
1493 |
if (*vm_flags & (VM_NOHUGEPAGE | VM_NO_THP)) |
a664b2d85 thp: madvise(MADV... |
1494 1495 1496 |
return -EINVAL; *vm_flags &= ~VM_HUGEPAGE; *vm_flags |= VM_NOHUGEPAGE; |
60ab3244e thp: khugepaged: ... |
1497 1498 1499 1500 1501 |
/* * Setting VM_NOHUGEPAGE will prevent khugepaged from scanning * this vma even if we leave the mm registered in khugepaged if * it got registered before VM_NOHUGEPAGE was set. */ |
a664b2d85 thp: madvise(MADV... |
1502 1503 |
break; } |
0af4e98b6 thp: madvise(MADV... |
1504 1505 1506 |
return 0; } |
ba76149f4 thp: khugepaged |
1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 |
static int __init khugepaged_slab_init(void) { mm_slot_cache = kmem_cache_create("khugepaged_mm_slot", sizeof(struct mm_slot), __alignof__(struct mm_slot), 0, NULL); if (!mm_slot_cache) return -ENOMEM; return 0; } static void __init khugepaged_slab_free(void) { kmem_cache_destroy(mm_slot_cache); mm_slot_cache = NULL; } static inline struct mm_slot *alloc_mm_slot(void) { if (!mm_slot_cache) /* initialization failed */ return NULL; return kmem_cache_zalloc(mm_slot_cache, GFP_KERNEL); } static inline void free_mm_slot(struct mm_slot *mm_slot) { kmem_cache_free(mm_slot_cache, mm_slot); } static int __init mm_slots_hash_init(void) { mm_slots_hash = kzalloc(MM_SLOTS_HASH_HEADS * sizeof(struct hlist_head), GFP_KERNEL); if (!mm_slots_hash) return -ENOMEM; return 0; } #if 0 static void __init mm_slots_hash_free(void) { kfree(mm_slots_hash); mm_slots_hash = NULL; } #endif static struct mm_slot *get_mm_slot(struct mm_struct *mm) { struct mm_slot *mm_slot; struct hlist_head *bucket; struct hlist_node *node; bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct)) % MM_SLOTS_HASH_HEADS]; hlist_for_each_entry(mm_slot, node, bucket, hash) { if (mm == mm_slot->mm) return mm_slot; } return NULL; } static void insert_to_mm_slots_hash(struct mm_struct *mm, struct mm_slot *mm_slot) { struct hlist_head *bucket; bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct)) % MM_SLOTS_HASH_HEADS]; mm_slot->mm = mm; hlist_add_head(&mm_slot->hash, bucket); } static inline int khugepaged_test_exit(struct mm_struct *mm) { return atomic_read(&mm->mm_users) == 0; } int __khugepaged_enter(struct mm_struct *mm) { struct mm_slot *mm_slot; int wakeup; mm_slot = alloc_mm_slot(); if (!mm_slot) return -ENOMEM; /* __khugepaged_exit() must not run from under us */ VM_BUG_ON(khugepaged_test_exit(mm)); if (unlikely(test_and_set_bit(MMF_VM_HUGEPAGE, &mm->flags))) { free_mm_slot(mm_slot); return 0; } spin_lock(&khugepaged_mm_lock); insert_to_mm_slots_hash(mm, mm_slot); /* * Insert just behind the scanning cursor, to let the area settle * down a little. */ wakeup = list_empty(&khugepaged_scan.mm_head); list_add_tail(&mm_slot->mm_node, &khugepaged_scan.mm_head); spin_unlock(&khugepaged_mm_lock); atomic_inc(&mm->mm_count); if (wakeup) wake_up_interruptible(&khugepaged_wait); return 0; } int khugepaged_enter_vma_merge(struct vm_area_struct *vma) { unsigned long hstart, hend; if (!vma->anon_vma) /* * Not yet faulted in so we will register later in the * page fault if needed. */ return 0; |
78f11a255 mm: thp: fix /dev... |
1626 |
if (vma->vm_ops) |
ba76149f4 thp: khugepaged |
1627 1628 |
/* khugepaged not yet working on file or special mappings */ return 0; |
78f11a255 mm: thp: fix /dev... |
1629 1630 1631 1632 1633 |
/* * If is_pfn_mapping() is true is_learn_pfn_mapping() must be * true too, verify it here. */ VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP); |
ba76149f4 thp: khugepaged |
1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 |
hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK; hend = vma->vm_end & HPAGE_PMD_MASK; if (hstart < hend) return khugepaged_enter(vma); return 0; } void __khugepaged_exit(struct mm_struct *mm) { struct mm_slot *mm_slot; int free = 0; spin_lock(&khugepaged_mm_lock); mm_slot = get_mm_slot(mm); if (mm_slot && khugepaged_scan.mm_slot != mm_slot) { hlist_del(&mm_slot->hash); list_del(&mm_slot->mm_node); free = 1; } |
d788e80a8 mm/huge_memory.c:... |
1653 |
spin_unlock(&khugepaged_mm_lock); |
ba76149f4 thp: khugepaged |
1654 1655 |
if (free) { |
ba76149f4 thp: khugepaged |
1656 1657 1658 1659 |
clear_bit(MMF_VM_HUGEPAGE, &mm->flags); free_mm_slot(mm_slot); mmdrop(mm); } else if (mm_slot) { |
ba76149f4 thp: khugepaged |
1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 |
/* * This is required to serialize against * khugepaged_test_exit() (which is guaranteed to run * under mmap sem read mode). Stop here (after we * return all pagetables will be destroyed) until * khugepaged has finished working on the pagetables * under the mmap_sem. */ down_write(&mm->mmap_sem); up_write(&mm->mmap_sem); |
d788e80a8 mm/huge_memory.c:... |
1670 |
} |
ba76149f4 thp: khugepaged |
1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 |
} static void release_pte_page(struct page *page) { /* 0 stands for page_is_file_cache(page) == false */ dec_zone_page_state(page, NR_ISOLATED_ANON + 0); unlock_page(page); putback_lru_page(page); } static void release_pte_pages(pte_t *pte, pte_t *_pte) { while (--_pte >= pte) { pte_t pteval = *_pte; if (!pte_none(pteval)) release_pte_page(pte_page(pteval)); } } static void release_all_pte_pages(pte_t *pte) { release_pte_pages(pte, pte + HPAGE_PMD_NR); } static int __collapse_huge_page_isolate(struct vm_area_struct *vma, unsigned long address, pte_t *pte) { struct page *page; pte_t *_pte; int referenced = 0, isolated = 0, none = 0; for (_pte = pte; _pte < pte+HPAGE_PMD_NR; _pte++, address += PAGE_SIZE) { pte_t pteval = *_pte; if (pte_none(pteval)) { if (++none <= khugepaged_max_ptes_none) continue; else { release_pte_pages(pte, _pte); goto out; } } if (!pte_present(pteval) || !pte_write(pteval)) { release_pte_pages(pte, _pte); goto out; } page = vm_normal_page(vma, address, pteval); if (unlikely(!page)) { release_pte_pages(pte, _pte); goto out; } VM_BUG_ON(PageCompound(page)); BUG_ON(!PageAnon(page)); VM_BUG_ON(!PageSwapBacked(page)); /* cannot use mapcount: can't collapse if there's a gup pin */ if (page_count(page) != 1) { release_pte_pages(pte, _pte); goto out; } /* * We can do it before isolate_lru_page because the * page can't be freed from under us. NOTE: PG_lock * is needed to serialize against split_huge_page * when invoked from the VM. */ if (!trylock_page(page)) { release_pte_pages(pte, _pte); goto out; } /* * Isolate the page to avoid collapsing an hugepage * currently in use by the VM. */ if (isolate_lru_page(page)) { unlock_page(page); release_pte_pages(pte, _pte); goto out; } /* 0 stands for page_is_file_cache(page) == false */ inc_zone_page_state(page, NR_ISOLATED_ANON + 0); VM_BUG_ON(!PageLocked(page)); VM_BUG_ON(PageLRU(page)); /* If there is no mapped pte young don't collapse the page */ |
8ee53820e thp: mmu_notifier... |
1756 1757 |
if (pte_young(pteval) || PageReferenced(page) || mmu_notifier_test_young(vma->vm_mm, address)) |
ba76149f4 thp: khugepaged |
1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 |
referenced = 1; } if (unlikely(!referenced)) release_all_pte_pages(pte); else isolated = 1; out: return isolated; } static void __collapse_huge_page_copy(pte_t *pte, struct page *page, struct vm_area_struct *vma, unsigned long address, spinlock_t *ptl) { pte_t *_pte; for (_pte = pte; _pte < pte+HPAGE_PMD_NR; _pte++) { pte_t pteval = *_pte; struct page *src_page; if (pte_none(pteval)) { clear_user_highpage(page, address); add_mm_counter(vma->vm_mm, MM_ANONPAGES, 1); } else { src_page = pte_page(pteval); copy_user_highpage(page, src_page, address, vma); VM_BUG_ON(page_mapcount(src_page) != 1); VM_BUG_ON(page_count(src_page) != 2); release_pte_page(src_page); /* * ptl mostly unnecessary, but preempt has to * be disabled to update the per-cpu stats * inside page_remove_rmap(). */ spin_lock(ptl); /* * paravirt calls inside pte_clear here are * superfluous. */ pte_clear(vma->vm_mm, address, _pte); page_remove_rmap(src_page); spin_unlock(ptl); free_page_and_swap_cache(src_page); } address += PAGE_SIZE; page++; } } static void collapse_huge_page(struct mm_struct *mm, unsigned long address, |
ce83d2174 thp: allocate mem... |
1810 |
struct page **hpage, |
5c4b4be3b mm: use correct n... |
1811 1812 |
struct vm_area_struct *vma, int node) |
ba76149f4 thp: khugepaged |
1813 |
{ |
ba76149f4 thp: khugepaged |
1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 |
pgd_t *pgd; pud_t *pud; pmd_t *pmd, _pmd; pte_t *pte; pgtable_t pgtable; struct page *new_page; spinlock_t *ptl; int isolated; unsigned long hstart, hend; VM_BUG_ON(address & ~HPAGE_PMD_MASK); |
0bbbc0b33 thp: add numa awa... |
1825 |
#ifndef CONFIG_NUMA |
692e0b354 mm: thp: optimize... |
1826 |
up_read(&mm->mmap_sem); |
ba76149f4 thp: khugepaged |
1827 |
VM_BUG_ON(!*hpage); |
ce83d2174 thp: allocate mem... |
1828 |
new_page = *hpage; |
0bbbc0b33 thp: add numa awa... |
1829 1830 |
#else VM_BUG_ON(*hpage); |
ce83d2174 thp: allocate mem... |
1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 |
/* * Allocate the page while the vma is still valid and under * the mmap_sem read mode so there is no memory allocation * later when we take the mmap_sem in write mode. This is more * friendly behavior (OTOH it may actually hide bugs) to * filesystems in userland with daemons allocating memory in * the userland I/O paths. Allocating memory with the * mmap_sem in read mode is good idea also to allow greater * scalability. */ |
5c4b4be3b mm: use correct n... |
1841 |
new_page = alloc_hugepage_vma(khugepaged_defrag(), vma, address, |
cc5d462f7 mm: use __GFP_OTH... |
1842 |
node, __GFP_OTHER_NODE); |
692e0b354 mm: thp: optimize... |
1843 1844 1845 1846 1847 1848 |
/* * After allocating the hugepage, release the mmap_sem read lock in * preparation for taking it in write mode. */ up_read(&mm->mmap_sem); |
ce83d2174 thp: allocate mem... |
1849 |
if (unlikely(!new_page)) { |
81ab4201f mm: add VM counte... |
1850 |
count_vm_event(THP_COLLAPSE_ALLOC_FAILED); |
ce83d2174 thp: allocate mem... |
1851 1852 1853 |
*hpage = ERR_PTR(-ENOMEM); return; } |
692e0b354 mm: thp: optimize... |
1854 |
#endif |
81ab4201f mm: add VM counte... |
1855 |
count_vm_event(THP_COLLAPSE_ALLOC); |
ce83d2174 thp: allocate mem... |
1856 |
if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) { |
692e0b354 mm: thp: optimize... |
1857 |
#ifdef CONFIG_NUMA |
ce83d2174 thp: allocate mem... |
1858 |
put_page(new_page); |
692e0b354 mm: thp: optimize... |
1859 |
#endif |
ce83d2174 thp: allocate mem... |
1860 1861 |
return; } |
ba76149f4 thp: khugepaged |
1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 |
/* * Prevent all access to pagetables with the exception of * gup_fast later hanlded by the ptep_clear_flush and the VM * handled by the anon_vma lock + PG_lock. */ down_write(&mm->mmap_sem); if (unlikely(khugepaged_test_exit(mm))) goto out; vma = find_vma(mm, address); hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK; hend = vma->vm_end & HPAGE_PMD_MASK; if (address < hstart || address + HPAGE_PMD_SIZE > hend) goto out; |
60ab3244e thp: khugepaged: ... |
1877 1878 |
if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) || (vma->vm_flags & VM_NOHUGEPAGE)) |
ba76149f4 thp: khugepaged |
1879 |
goto out; |
78f11a255 mm: thp: fix /dev... |
1880 |
if (!vma->anon_vma || vma->vm_ops) |
ba76149f4 thp: khugepaged |
1881 |
goto out; |
a7d6e4ecd thp: prevent huge... |
1882 1883 |
if (is_vma_temporary_stack(vma)) goto out; |
78f11a255 mm: thp: fix /dev... |
1884 1885 1886 1887 1888 |
/* * If is_pfn_mapping() is true is_learn_pfn_mapping() must be * true too, verify it here. */ VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP); |
ba76149f4 thp: khugepaged |
1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 |
pgd = pgd_offset(mm, address); if (!pgd_present(*pgd)) goto out; pud = pud_offset(pgd, address); if (!pud_present(*pud)) goto out; pmd = pmd_offset(pud, address); /* pmd can't go away or become huge under us */ if (!pmd_present(*pmd) || pmd_trans_huge(*pmd)) goto out; |
ba76149f4 thp: khugepaged |
1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 |
anon_vma_lock(vma->anon_vma); pte = pte_offset_map(pmd, address); ptl = pte_lockptr(mm, pmd); spin_lock(&mm->page_table_lock); /* probably unnecessary */ /* * After this gup_fast can't run anymore. This also removes * any huge TLB entry from the CPU so we won't allow * huge and small TLB entries for the same virtual address * to avoid the risk of CPU bugs in that area. */ _pmd = pmdp_clear_flush_notify(vma, address, pmd); spin_unlock(&mm->page_table_lock); spin_lock(ptl); isolated = __collapse_huge_page_isolate(vma, address, pte); spin_unlock(ptl); |
ba76149f4 thp: khugepaged |
1920 1921 |
if (unlikely(!isolated)) { |
453c71926 thp: keep highpte... |
1922 |
pte_unmap(pte); |
ba76149f4 thp: khugepaged |
1923 1924 1925 1926 1927 |
spin_lock(&mm->page_table_lock); BUG_ON(!pmd_none(*pmd)); set_pmd_at(mm, address, pmd, _pmd); spin_unlock(&mm->page_table_lock); anon_vma_unlock(vma->anon_vma); |
ce83d2174 thp: allocate mem... |
1928 |
goto out; |
ba76149f4 thp: khugepaged |
1929 1930 1931 1932 1933 1934 1935 1936 1937 |
} /* * All pages are isolated and locked so anon_vma rmap * can't run anymore. */ anon_vma_unlock(vma->anon_vma); __collapse_huge_page_copy(pte, new_page, vma, address, ptl); |
453c71926 thp: keep highpte... |
1938 |
pte_unmap(pte); |
ba76149f4 thp: khugepaged |
1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 |
__SetPageUptodate(new_page); pgtable = pmd_pgtable(_pmd); VM_BUG_ON(page_count(pgtable) != 1); VM_BUG_ON(page_mapcount(pgtable) != 0); _pmd = mk_pmd(new_page, vma->vm_page_prot); _pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma); _pmd = pmd_mkhuge(_pmd); /* * spin_lock() below is not the equivalent of smp_wmb(), so * this is needed to avoid the copy_huge_page writes to become * visible after the set_pmd_at() write. */ smp_wmb(); spin_lock(&mm->page_table_lock); BUG_ON(!pmd_none(*pmd)); page_add_new_anon_rmap(new_page, vma, address); set_pmd_at(mm, address, pmd, _pmd); |
35d8c7ad7 mm/huge_memory: f... |
1959 |
update_mmu_cache(vma, address, _pmd); |
ba76149f4 thp: khugepaged |
1960 1961 1962 |
prepare_pmd_huge_pte(pgtable, mm); mm->nr_ptes--; spin_unlock(&mm->page_table_lock); |
0bbbc0b33 thp: add numa awa... |
1963 |
#ifndef CONFIG_NUMA |
ba76149f4 thp: khugepaged |
1964 |
*hpage = NULL; |
0bbbc0b33 thp: add numa awa... |
1965 |
#endif |
ba76149f4 thp: khugepaged |
1966 |
khugepaged_pages_collapsed++; |
ce83d2174 thp: allocate mem... |
1967 |
out_up_write: |
ba76149f4 thp: khugepaged |
1968 |
up_write(&mm->mmap_sem); |
0bbbc0b33 thp: add numa awa... |
1969 |
return; |
ce83d2174 thp: allocate mem... |
1970 |
out: |
678ff896a memcg: fix leak o... |
1971 |
mem_cgroup_uncharge_page(new_page); |
0bbbc0b33 thp: add numa awa... |
1972 1973 1974 |
#ifdef CONFIG_NUMA put_page(new_page); #endif |
ce83d2174 thp: allocate mem... |
1975 |
goto out_up_write; |
ba76149f4 thp: khugepaged |
1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 |
} static int khugepaged_scan_pmd(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, struct page **hpage) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *pte, *_pte; int ret = 0, referenced = 0, none = 0; struct page *page; unsigned long _address; spinlock_t *ptl; |
5c4b4be3b mm: use correct n... |
1991 |
int node = -1; |
ba76149f4 thp: khugepaged |
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 |
VM_BUG_ON(address & ~HPAGE_PMD_MASK); pgd = pgd_offset(mm, address); if (!pgd_present(*pgd)) goto out; pud = pud_offset(pgd, address); if (!pud_present(*pud)) goto out; pmd = pmd_offset(pud, address); if (!pmd_present(*pmd) || pmd_trans_huge(*pmd)) goto out; pte = pte_offset_map_lock(mm, pmd, address, &ptl); for (_address = address, _pte = pte; _pte < pte+HPAGE_PMD_NR; _pte++, _address += PAGE_SIZE) { pte_t pteval = *_pte; if (pte_none(pteval)) { if (++none <= khugepaged_max_ptes_none) continue; else goto out_unmap; } if (!pte_present(pteval) || !pte_write(pteval)) goto out_unmap; page = vm_normal_page(vma, _address, pteval); if (unlikely(!page)) goto out_unmap; |
5c4b4be3b mm: use correct n... |
2022 2023 2024 2025 2026 2027 2028 |
/* * Chose the node of the first page. This could * be more sophisticated and look at more pages, * but isn't for now. */ if (node == -1) node = page_to_nid(page); |
ba76149f4 thp: khugepaged |
2029 2030 2031 2032 2033 2034 |
VM_BUG_ON(PageCompound(page)); if (!PageLRU(page) || PageLocked(page) || !PageAnon(page)) goto out_unmap; /* cannot use mapcount: can't collapse if there's a gup pin */ if (page_count(page) != 1) goto out_unmap; |
8ee53820e thp: mmu_notifier... |
2035 2036 |
if (pte_young(pteval) || PageReferenced(page) || mmu_notifier_test_young(vma->vm_mm, address)) |
ba76149f4 thp: khugepaged |
2037 2038 2039 2040 2041 2042 |
referenced = 1; } if (referenced) ret = 1; out_unmap: pte_unmap_unlock(pte, ptl); |
ce83d2174 thp: allocate mem... |
2043 2044 |
if (ret) /* collapse_huge_page will return with the mmap_sem released */ |
5c4b4be3b mm: use correct n... |
2045 |
collapse_huge_page(mm, address, hpage, vma, node); |
ba76149f4 thp: khugepaged |
2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 |
out: return ret; } static void collect_mm_slot(struct mm_slot *mm_slot) { struct mm_struct *mm = mm_slot->mm; VM_BUG_ON(!spin_is_locked(&khugepaged_mm_lock)); if (khugepaged_test_exit(mm)) { /* free mm_slot */ hlist_del(&mm_slot->hash); list_del(&mm_slot->mm_node); /* * Not strictly needed because the mm exited already. * * clear_bit(MMF_VM_HUGEPAGE, &mm->flags); */ /* khugepaged_mm_lock actually not necessary for the below */ free_mm_slot(mm_slot); mmdrop(mm); } } static unsigned int khugepaged_scan_mm_slot(unsigned int pages, struct page **hpage) |
2f1da6421 mm/huge_memory.c:... |
2075 2076 |
__releases(&khugepaged_mm_lock) __acquires(&khugepaged_mm_lock) |
ba76149f4 thp: khugepaged |
2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 |
{ struct mm_slot *mm_slot; struct mm_struct *mm; struct vm_area_struct *vma; int progress = 0; VM_BUG_ON(!pages); VM_BUG_ON(!spin_is_locked(&khugepaged_mm_lock)); if (khugepaged_scan.mm_slot) mm_slot = khugepaged_scan.mm_slot; else { mm_slot = list_entry(khugepaged_scan.mm_head.next, struct mm_slot, mm_node); khugepaged_scan.address = 0; khugepaged_scan.mm_slot = mm_slot; } spin_unlock(&khugepaged_mm_lock); mm = mm_slot->mm; down_read(&mm->mmap_sem); if (unlikely(khugepaged_test_exit(mm))) vma = NULL; else vma = find_vma(mm, khugepaged_scan.address); progress++; for (; vma; vma = vma->vm_next) { unsigned long hstart, hend; cond_resched(); if (unlikely(khugepaged_test_exit(mm))) { progress++; break; } |
60ab3244e thp: khugepaged: ... |
2112 2113 2114 |
if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) || (vma->vm_flags & VM_NOHUGEPAGE)) { |
a7d6e4ecd thp: prevent huge... |
2115 |
skip: |
ba76149f4 thp: khugepaged |
2116 2117 2118 |
progress++; continue; } |
78f11a255 mm: thp: fix /dev... |
2119 |
if (!vma->anon_vma || vma->vm_ops) |
a7d6e4ecd thp: prevent huge... |
2120 2121 2122 |
goto skip; if (is_vma_temporary_stack(vma)) goto skip; |
78f11a255 mm: thp: fix /dev... |
2123 2124 2125 2126 2127 2128 |
/* * If is_pfn_mapping() is true is_learn_pfn_mapping() * must be true too, verify it here. */ VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP); |
ba76149f4 thp: khugepaged |
2129 2130 2131 |
hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK; hend = vma->vm_end & HPAGE_PMD_MASK; |
a7d6e4ecd thp: prevent huge... |
2132 2133 2134 2135 |
if (hstart >= hend) goto skip; if (khugepaged_scan.address > hend) goto skip; |
ba76149f4 thp: khugepaged |
2136 2137 |
if (khugepaged_scan.address < hstart) khugepaged_scan.address = hstart; |
a7d6e4ecd thp: prevent huge... |
2138 |
VM_BUG_ON(khugepaged_scan.address & ~HPAGE_PMD_MASK); |
ba76149f4 thp: khugepaged |
2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 |
while (khugepaged_scan.address < hend) { int ret; cond_resched(); if (unlikely(khugepaged_test_exit(mm))) goto breakouterloop; VM_BUG_ON(khugepaged_scan.address < hstart || khugepaged_scan.address + HPAGE_PMD_SIZE > hend); ret = khugepaged_scan_pmd(mm, vma, khugepaged_scan.address, hpage); /* move to next address */ khugepaged_scan.address += HPAGE_PMD_SIZE; progress += HPAGE_PMD_NR; if (ret) /* we released mmap_sem so break loop */ goto breakouterloop_mmap_sem; if (progress >= pages) goto breakouterloop; } } breakouterloop: up_read(&mm->mmap_sem); /* exit_mmap will destroy ptes after this */ breakouterloop_mmap_sem: spin_lock(&khugepaged_mm_lock); |
a7d6e4ecd thp: prevent huge... |
2167 |
VM_BUG_ON(khugepaged_scan.mm_slot != mm_slot); |
ba76149f4 thp: khugepaged |
2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 |
/* * Release the current mm_slot if this mm is about to die, or * if we scanned all vmas of this mm. */ if (khugepaged_test_exit(mm) || !vma) { /* * Make sure that if mm_users is reaching zero while * khugepaged runs here, khugepaged_exit will find * mm_slot not pointing to the exiting mm. */ if (mm_slot->mm_node.next != &khugepaged_scan.mm_head) { khugepaged_scan.mm_slot = list_entry( mm_slot->mm_node.next, struct mm_slot, mm_node); khugepaged_scan.address = 0; } else { khugepaged_scan.mm_slot = NULL; khugepaged_full_scans++; } collect_mm_slot(mm_slot); } return progress; } static int khugepaged_has_work(void) { return !list_empty(&khugepaged_scan.mm_head) && khugepaged_enabled(); } static int khugepaged_wait_event(void) { return !list_empty(&khugepaged_scan.mm_head) || !khugepaged_enabled(); } static void khugepaged_do_scan(struct page **hpage) { unsigned int progress = 0, pass_through_head = 0; unsigned int pages = khugepaged_pages_to_scan; barrier(); /* write khugepaged_pages_to_scan to local stack */ while (progress < pages) { cond_resched(); |
0bbbc0b33 thp: add numa awa... |
2215 |
#ifndef CONFIG_NUMA |
ba76149f4 thp: khugepaged |
2216 2217 |
if (!*hpage) { *hpage = alloc_hugepage(khugepaged_defrag()); |
81ab4201f mm: add VM counte... |
2218 2219 |
if (unlikely(!*hpage)) { count_vm_event(THP_COLLAPSE_ALLOC_FAILED); |
ba76149f4 thp: khugepaged |
2220 |
break; |
81ab4201f mm: add VM counte... |
2221 2222 |
} count_vm_event(THP_COLLAPSE_ALLOC); |
ba76149f4 thp: khugepaged |
2223 |
} |
0bbbc0b33 thp: add numa awa... |
2224 2225 2226 2227 |
#else if (IS_ERR(*hpage)) break; #endif |
ba76149f4 thp: khugepaged |
2228 |
|
878aee7d6 thp: freeze khuge... |
2229 2230 |
if (unlikely(kthread_should_stop() || freezing(current))) break; |
ba76149f4 thp: khugepaged |
2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 |
spin_lock(&khugepaged_mm_lock); if (!khugepaged_scan.mm_slot) pass_through_head++; if (khugepaged_has_work() && pass_through_head < 2) progress += khugepaged_scan_mm_slot(pages - progress, hpage); else progress = pages; spin_unlock(&khugepaged_mm_lock); } } |
0bbbc0b33 thp: add numa awa... |
2243 2244 |
static void khugepaged_alloc_sleep(void) { |
1dfb059b9 thp: reduce khuge... |
2245 2246 |
wait_event_freezable_timeout(khugepaged_wait, false, msecs_to_jiffies(khugepaged_alloc_sleep_millisecs)); |
0bbbc0b33 thp: add numa awa... |
2247 2248 2249 |
} #ifndef CONFIG_NUMA |
ba76149f4 thp: khugepaged |
2250 2251 2252 2253 2254 2255 |
static struct page *khugepaged_alloc_hugepage(void) { struct page *hpage; do { hpage = alloc_hugepage(khugepaged_defrag()); |
81ab4201f mm: add VM counte... |
2256 2257 |
if (!hpage) { count_vm_event(THP_COLLAPSE_ALLOC_FAILED); |
0bbbc0b33 thp: add numa awa... |
2258 |
khugepaged_alloc_sleep(); |
81ab4201f mm: add VM counte... |
2259 2260 |
} else count_vm_event(THP_COLLAPSE_ALLOC); |
ba76149f4 thp: khugepaged |
2261 2262 2263 2264 |
} while (unlikely(!hpage) && likely(khugepaged_enabled())); return hpage; } |
0bbbc0b33 thp: add numa awa... |
2265 |
#endif |
ba76149f4 thp: khugepaged |
2266 2267 2268 2269 |
static void khugepaged_loop(void) { struct page *hpage; |
0bbbc0b33 thp: add numa awa... |
2270 2271 2272 |
#ifdef CONFIG_NUMA hpage = NULL; #endif |
ba76149f4 thp: khugepaged |
2273 |
while (likely(khugepaged_enabled())) { |
0bbbc0b33 thp: add numa awa... |
2274 |
#ifndef CONFIG_NUMA |
ba76149f4 thp: khugepaged |
2275 |
hpage = khugepaged_alloc_hugepage(); |
f300ea499 mm: remove khugep... |
2276 |
if (unlikely(!hpage)) |
ba76149f4 thp: khugepaged |
2277 |
break; |
0bbbc0b33 thp: add numa awa... |
2278 2279 2280 2281 2282 2283 |
#else if (IS_ERR(hpage)) { khugepaged_alloc_sleep(); hpage = NULL; } #endif |
ba76149f4 thp: khugepaged |
2284 2285 |
khugepaged_do_scan(&hpage); |
0bbbc0b33 thp: add numa awa... |
2286 |
#ifndef CONFIG_NUMA |
ba76149f4 thp: khugepaged |
2287 2288 |
if (hpage) put_page(hpage); |
0bbbc0b33 thp: add numa awa... |
2289 |
#endif |
878aee7d6 thp: freeze khuge... |
2290 2291 2292 |
try_to_freeze(); if (unlikely(kthread_should_stop())) break; |
ba76149f4 thp: khugepaged |
2293 |
if (khugepaged_has_work()) { |
ba76149f4 thp: khugepaged |
2294 2295 |
if (!khugepaged_scan_sleep_millisecs) continue; |
1dfb059b9 thp: reduce khuge... |
2296 2297 |
wait_event_freezable_timeout(khugepaged_wait, false, msecs_to_jiffies(khugepaged_scan_sleep_millisecs)); |
ba76149f4 thp: khugepaged |
2298 |
} else if (khugepaged_enabled()) |
878aee7d6 thp: freeze khuge... |
2299 2300 |
wait_event_freezable(khugepaged_wait, khugepaged_wait_event()); |
ba76149f4 thp: khugepaged |
2301 2302 2303 2304 2305 2306 |
} } static int khugepaged(void *none) { struct mm_slot *mm_slot; |
878aee7d6 thp: freeze khuge... |
2307 |
set_freezable(); |
ba76149f4 thp: khugepaged |
2308 2309 2310 2311 2312 2313 2314 |
set_user_nice(current, 19); /* serialize with start_khugepaged() */ mutex_lock(&khugepaged_mutex); for (;;) { mutex_unlock(&khugepaged_mutex); |
a7d6e4ecd thp: prevent huge... |
2315 |
VM_BUG_ON(khugepaged_thread != current); |
ba76149f4 thp: khugepaged |
2316 |
khugepaged_loop(); |
a7d6e4ecd thp: prevent huge... |
2317 |
VM_BUG_ON(khugepaged_thread != current); |
ba76149f4 thp: khugepaged |
2318 2319 2320 2321 |
mutex_lock(&khugepaged_mutex); if (!khugepaged_enabled()) break; |
878aee7d6 thp: freeze khuge... |
2322 2323 |
if (unlikely(kthread_should_stop())) break; |
ba76149f4 thp: khugepaged |
2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 |
} spin_lock(&khugepaged_mm_lock); mm_slot = khugepaged_scan.mm_slot; khugepaged_scan.mm_slot = NULL; if (mm_slot) collect_mm_slot(mm_slot); spin_unlock(&khugepaged_mm_lock); khugepaged_thread = NULL; mutex_unlock(&khugepaged_mutex); return 0; } |
71e3aac07 thp: transparent ... |
2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 |
void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd) { struct page *page; spin_lock(&mm->page_table_lock); if (unlikely(!pmd_trans_huge(*pmd))) { spin_unlock(&mm->page_table_lock); return; } page = pmd_page(*pmd); VM_BUG_ON(!page_count(page)); get_page(page); spin_unlock(&mm->page_table_lock); split_huge_page(page); put_page(page); BUG_ON(pmd_trans_huge(*pmd)); } |
94fcc585f thp: avoid breaki... |
2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 |
static void split_huge_page_address(struct mm_struct *mm, unsigned long address) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; VM_BUG_ON(!(address & ~HPAGE_PMD_MASK)); pgd = pgd_offset(mm, address); if (!pgd_present(*pgd)) return; pud = pud_offset(pgd, address); if (!pud_present(*pud)) return; pmd = pmd_offset(pud, address); if (!pmd_present(*pmd)) return; /* * Caller holds the mmap_sem write mode, so a huge pmd cannot * materialize from under us. */ split_huge_page_pmd(mm, pmd); } void __vma_adjust_trans_huge(struct vm_area_struct *vma, unsigned long start, unsigned long end, long adjust_next) { /* * If the new start address isn't hpage aligned and it could * previously contain an hugepage: check if we need to split * an huge pmd. */ if (start & ~HPAGE_PMD_MASK && (start & HPAGE_PMD_MASK) >= vma->vm_start && (start & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= vma->vm_end) split_huge_page_address(vma->vm_mm, start); /* * If the new end address isn't hpage aligned and it could * previously contain an hugepage: check if we need to split * an huge pmd. */ if (end & ~HPAGE_PMD_MASK && (end & HPAGE_PMD_MASK) >= vma->vm_start && (end & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= vma->vm_end) split_huge_page_address(vma->vm_mm, end); /* * If we're also updating the vma->vm_next->vm_start, if the new * vm_next->vm_start isn't page aligned and it could previously * contain an hugepage: check if we need to split an huge pmd. */ if (adjust_next > 0) { struct vm_area_struct *next = vma->vm_next; unsigned long nstart = next->vm_start; nstart += adjust_next << PAGE_SHIFT; if (nstart & ~HPAGE_PMD_MASK && (nstart & HPAGE_PMD_MASK) >= next->vm_start && (nstart & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= next->vm_end) split_huge_page_address(next->vm_mm, nstart); } } |