Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[cascardo/linux.git] / mm / huge_memory.c

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 66675ee..9ed5853 100644 (file)
--- 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)
@@ -2794,15 +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;
        }
 
@@ -3026,8 +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);
 }