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-rw-r--r--mm/huge_memory.c42
1 files changed, 26 insertions, 16 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b49ee126d4d1..9ed58530f695 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -89,6 +89,7 @@ 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 unsigned long khugepaged_sleep_expire;
static struct task_struct *khugepaged_thread __read_mostly;
static DEFINE_MUTEX(khugepaged_mutex);
static DEFINE_SPINLOCK(khugepaged_mm_lock);
@@ -467,6 +468,7 @@ static ssize_t scan_sleep_millisecs_store(struct kobject *kobj,
return -EINVAL;
khugepaged_scan_sleep_millisecs = msecs;
+ khugepaged_sleep_expire = 0;
wake_up_interruptible(&khugepaged_wait);
return count;
@@ -494,6 +496,7 @@ static ssize_t alloc_sleep_millisecs_store(struct kobject *kobj,
return -EINVAL;
khugepaged_alloc_sleep_millisecs = msecs;
+ khugepaged_sleep_expire = 0;
wake_up_interruptible(&khugepaged_wait);
return count;
@@ -764,10 +767,7 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
static inline pmd_t mk_huge_pmd(struct page *page, pgprot_t prot)
{
- pmd_t entry;
- entry = mk_pmd(page, prot);
- entry = pmd_mkhuge(entry);
- return entry;
+ return pmd_mkhuge(mk_pmd(page, prot));
}
static inline struct list_head *page_deferred_list(struct page *page)
@@ -1013,6 +1013,7 @@ int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
insert_pfn_pmd(vma, addr, pmd, pfn, pgprot, write);
return VM_FAULT_NOPAGE;
}
+EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd);
static void touch_pmd(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd)
@@ -1698,20 +1699,17 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
return 1;
}
-bool move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
- unsigned long old_addr,
+bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
unsigned long new_addr, unsigned long old_end,
pmd_t *old_pmd, pmd_t *new_pmd)
{
spinlock_t *old_ptl, *new_ptl;
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))
+ old_end - old_addr < HPAGE_PMD_SIZE)
return false;
/*
@@ -2797,15 +2795,25 @@ static void khugepaged_do_scan(void)
put_page(hpage);
}
+static bool khugepaged_should_wakeup(void)
+{
+ return kthread_should_stop() ||
+ time_after_eq(jiffies, khugepaged_sleep_expire);
+}
+
static void khugepaged_wait_work(void)
{
if (khugepaged_has_work()) {
- if (!khugepaged_scan_sleep_millisecs)
+ const unsigned long scan_sleep_jiffies =
+ msecs_to_jiffies(khugepaged_scan_sleep_millisecs);
+
+ if (!scan_sleep_jiffies)
return;
+ khugepaged_sleep_expire = jiffies + scan_sleep_jiffies;
wait_event_freezable_timeout(khugepaged_wait,
- kthread_should_stop(),
- msecs_to_jiffies(khugepaged_scan_sleep_millisecs));
+ khugepaged_should_wakeup(),
+ scan_sleep_jiffies);
return;
}
@@ -3029,8 +3037,10 @@ void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
return;
/*
- * Caller holds the mmap_sem write mode, so a huge pmd cannot
- * materialize from under us.
+ * Caller holds the mmap_sem write mode or the anon_vma lock,
+ * so a huge pmd cannot materialize from under us (khugepaged
+ * holds both the mmap_sem write mode and the anon_vma lock
+ * write mode).
*/
__split_huge_pmd(vma, pmd, address, freeze);
}
@@ -3113,7 +3123,7 @@ static void __split_huge_page_tail(struct page *head, int tail,
VM_BUG_ON_PAGE(page_ref_count(page_tail) != 0, page_tail);
/*
- * tail_page->_count is zero and not changing from under us. But
+ * tail_page->_refcount 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_inc(), we
* would then run atomic_set() concurrently with
@@ -3340,7 +3350,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
if (mlocked)
lru_add_drain();
- /* Prevent deferred_split_scan() touching ->_count */
+ /* Prevent deferred_split_scan() touching ->_refcount */
spin_lock_irqsave(&pgdata->split_queue_lock, flags);
count = page_count(head);
mapcount = total_mapcount(head);