#include <linux/mm_inline.h>
#include <linux/kthread.h>
#include <linux/khugepaged.h>
+#include <linux/freezer.h>
+#include <linux/mman.h>
#include <asm/tlb.h>
#include <asm/pgalloc.h>
#include "internal.h"
* allocations.
*/
unsigned long transparent_hugepage_flags __read_mostly =
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS
(1<<TRANSPARENT_HUGEPAGE_FLAG)|
+#endif
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE_MADVISE
+ (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)|
+#endif
+ (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)|
(1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG);
/* default scan 8*512 pte (or vmas) every 30 second */
.mm_head = LIST_HEAD_INIT(khugepaged_scan.mm_head),
};
+
+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);
+
static int start_khugepaged(void)
{
int err = 0;
mutex_unlock(&khugepaged_mutex);
if (wakeup)
wake_up_interruptible(&khugepaged_wait);
+
+ set_recommended_min_free_kbytes();
} else
/* wakeup to exit */
wake_up_interruptible(&khugepaged_wait);
ret = err;
}
+ 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();
+
return ret;
}
static struct kobj_attribute enabled_attr =
int err;
#ifdef CONFIG_SYSFS
static struct kobject *hugepage_kobj;
+#endif
+
+ err = -EINVAL;
+ if (!has_transparent_hugepage()) {
+ transparent_hugepage_flags = 0;
+ goto out;
+ }
+#ifdef CONFIG_SYSFS
err = -ENOMEM;
hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj);
if (unlikely(!hugepage_kobj)) {
goto out;
}
+ /*
+ * 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;
+
start_khugepaged();
+ set_recommended_min_free_kbytes();
+
out:
return err;
}
return ret;
}
+static inline gfp_t alloc_hugepage_gfpmask(int defrag)
+{
+ return GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT);
+}
+
+static inline struct page *alloc_hugepage_vma(int defrag,
+ struct vm_area_struct *vma,
+ unsigned long haddr)
+{
+ return alloc_pages_vma(alloc_hugepage_gfpmask(defrag),
+ HPAGE_PMD_ORDER, vma, haddr);
+}
+
+#ifndef CONFIG_NUMA
static inline struct page *alloc_hugepage(int defrag)
{
- return alloc_pages(GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT),
+ return alloc_pages(alloc_hugepage_gfpmask(defrag),
HPAGE_PMD_ORDER);
}
+#endif
int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, pmd_t *pmd,
return VM_FAULT_OOM;
if (unlikely(khugepaged_enter(vma)))
return VM_FAULT_OOM;
- page = alloc_hugepage(transparent_hugepage_defrag(vma));
+ page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),
+ vma, haddr);
if (unlikely(!page))
goto out;
if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) {
if (transparent_hugepage_enabled(vma) &&
!transparent_hugepage_debug_cow())
- new_page = alloc_hugepage(transparent_hugepage_defrag(vma));
+ new_page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),
+ vma, haddr);
else
new_page = NULL;
goto out;
if (pmd_page(*pmd) != page)
goto out;
- VM_BUG_ON(flag == PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG &&
- pmd_trans_splitting(*pmd));
+ /*
+ * 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;
if (pmd_trans_huge(*pmd)) {
VM_BUG_ON(flag == PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG &&
!pmd_trans_splitting(*pmd));
int i;
unsigned long head_index = page->index;
struct zone *zone = page_zone(page);
+ int zonestat;
/* prevent PageLRU to go away from under us, and freeze lru stats */
spin_lock_irq(&zone->lru_lock);
BUG_ON(!PageDirty(page_tail));
BUG_ON(!PageSwapBacked(page_tail));
+ mem_cgroup_split_huge_fixup(page, page_tail);
+
lru_add_page_tail(zone, page, page_tail);
}
__dec_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
__mod_zone_page_state(zone, NR_ANON_PAGES, HPAGE_PMD_NR);
+ /*
+ * 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));
+ }
+
ClearPageCompound(page);
compound_unlock(page);
spin_unlock_irq(&zone->lru_lock);
return ret;
}
-int hugepage_madvise(unsigned long *vm_flags)
+int hugepage_madvise(struct vm_area_struct *vma,
+ unsigned long *vm_flags, int advice)
{
- /*
- * Be somewhat over-protective like KSM for now!
- */
- if (*vm_flags & (VM_HUGEPAGE | VM_SHARED | VM_MAYSHARE |
- VM_PFNMAP | VM_IO | VM_DONTEXPAND |
- VM_RESERVED | VM_HUGETLB | VM_INSERTPAGE |
- VM_MIXEDMAP | VM_SAO))
- return -EINVAL;
-
- *vm_flags |= VM_HUGEPAGE;
+ switch (advice) {
+ case MADV_HUGEPAGE:
+ /*
+ * Be somewhat over-protective like KSM for now!
+ */
+ if (*vm_flags & (VM_HUGEPAGE |
+ VM_SHARED | VM_MAYSHARE |
+ VM_PFNMAP | VM_IO | VM_DONTEXPAND |
+ VM_RESERVED | VM_HUGETLB | VM_INSERTPAGE |
+ VM_MIXEDMAP | VM_SAO))
+ return -EINVAL;
+ *vm_flags &= ~VM_NOHUGEPAGE;
+ *vm_flags |= VM_HUGEPAGE;
+ /*
+ * 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;
+ break;
+ case MADV_NOHUGEPAGE:
+ /*
+ * Be somewhat over-protective like KSM for now!
+ */
+ if (*vm_flags & (VM_NOHUGEPAGE |
+ VM_SHARED | VM_MAYSHARE |
+ VM_PFNMAP | VM_IO | VM_DONTEXPAND |
+ VM_RESERVED | VM_HUGETLB | VM_INSERTPAGE |
+ VM_MIXEDMAP | VM_SAO))
+ return -EINVAL;
+ *vm_flags &= ~VM_HUGEPAGE;
+ *vm_flags |= VM_NOHUGEPAGE;
+ /*
+ * 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.
+ */
+ break;
+ }
return 0;
}
VM_BUG_ON(PageLRU(page));
/* If there is no mapped pte young don't collapse the page */
- if (pte_young(pteval))
+ if (pte_young(pteval) || PageReferenced(page) ||
+ mmu_notifier_test_young(vma->vm_mm, address))
referenced = 1;
}
if (unlikely(!referenced))
static void collapse_huge_page(struct mm_struct *mm,
unsigned long address,
- struct page **hpage)
+ struct page **hpage,
+ struct vm_area_struct *vma)
{
- struct vm_area_struct *vma;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd, _pmd;
unsigned long hstart, hend;
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+#ifndef CONFIG_NUMA
VM_BUG_ON(!*hpage);
+ new_page = *hpage;
+#else
+ VM_BUG_ON(*hpage);
+ /*
+ * 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.
+ */
+ new_page = alloc_hugepage_vma(khugepaged_defrag(), vma, address);
+ if (unlikely(!new_page)) {
+ up_read(&mm->mmap_sem);
+ *hpage = ERR_PTR(-ENOMEM);
+ return;
+ }
+#endif
+ if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
+ up_read(&mm->mmap_sem);
+ put_page(new_page);
+ return;
+ }
+
+ /* after allocating the hugepage upgrade to mmap_sem write mode */
+ up_read(&mm->mmap_sem);
/*
* Prevent all access to pagetables with the exception of
if (address < hstart || address + HPAGE_PMD_SIZE > hend)
goto out;
- if (!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always())
+ if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) ||
+ (vma->vm_flags & VM_NOHUGEPAGE))
goto out;
/* VM_PFNMAP vmas may have vm_ops null but vm_file set */
if (!pmd_present(*pmd) || pmd_trans_huge(*pmd))
goto out;
- new_page = *hpage;
- if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL)))
- goto out;
-
anon_vma_lock(vma->anon_vma);
pte = pte_offset_map(pmd, address);
spin_lock(ptl);
isolated = __collapse_huge_page_isolate(vma, address, pte);
spin_unlock(ptl);
- pte_unmap(pte);
if (unlikely(!isolated)) {
+ pte_unmap(pte);
spin_lock(&mm->page_table_lock);
BUG_ON(!pmd_none(*pmd));
set_pmd_at(mm, address, pmd, _pmd);
anon_vma_unlock(vma->anon_vma);
__collapse_huge_page_copy(pte, new_page, vma, address, ptl);
+ pte_unmap(pte);
__SetPageUptodate(new_page);
pgtable = pmd_pgtable(_pmd);
VM_BUG_ON(page_count(pgtable) != 1);
mm->nr_ptes--;
spin_unlock(&mm->page_table_lock);
+#ifndef CONFIG_NUMA
*hpage = NULL;
+#endif
khugepaged_pages_collapsed++;
-out:
+out_up_write:
up_write(&mm->mmap_sem);
+ return;
+
+out:
+#ifdef CONFIG_NUMA
+ put_page(new_page);
+#endif
+ goto out_up_write;
}
static int khugepaged_scan_pmd(struct mm_struct *mm,
/* cannot use mapcount: can't collapse if there's a gup pin */
if (page_count(page) != 1)
goto out_unmap;
- if (pte_young(pteval))
+ if (pte_young(pteval) || PageReferenced(page) ||
+ mmu_notifier_test_young(vma->vm_mm, address))
referenced = 1;
}
if (referenced)
ret = 1;
out_unmap:
pte_unmap_unlock(pte, ptl);
- if (ret) {
- up_read(&mm->mmap_sem);
- collapse_huge_page(mm, address, hpage);
- }
+ if (ret)
+ /* collapse_huge_page will return with the mmap_sem released */
+ collapse_huge_page(mm, address, hpage, vma);
out:
return ret;
}
break;
}
- if (!(vma->vm_flags & VM_HUGEPAGE) &&
- !khugepaged_always()) {
+ if ((!(vma->vm_flags & VM_HUGEPAGE) &&
+ !khugepaged_always()) ||
+ (vma->vm_flags & VM_NOHUGEPAGE)) {
progress++;
continue;
}
while (progress < pages) {
cond_resched();
+#ifndef CONFIG_NUMA
if (!*hpage) {
*hpage = alloc_hugepage(khugepaged_defrag());
if (unlikely(!*hpage))
break;
}
+#else
+ if (IS_ERR(*hpage))
+ break;
+#endif
+
+ if (unlikely(kthread_should_stop() || freezing(current)))
+ break;
spin_lock(&khugepaged_mm_lock);
if (!khugepaged_scan.mm_slot)
}
}
+static void khugepaged_alloc_sleep(void)
+{
+ DEFINE_WAIT(wait);
+ add_wait_queue(&khugepaged_wait, &wait);
+ schedule_timeout_interruptible(
+ msecs_to_jiffies(
+ khugepaged_alloc_sleep_millisecs));
+ remove_wait_queue(&khugepaged_wait, &wait);
+}
+
+#ifndef CONFIG_NUMA
static struct page *khugepaged_alloc_hugepage(void)
{
struct page *hpage;
do {
hpage = alloc_hugepage(khugepaged_defrag());
- if (!hpage) {
- DEFINE_WAIT(wait);
- add_wait_queue(&khugepaged_wait, &wait);
- schedule_timeout_interruptible(
- msecs_to_jiffies(
- khugepaged_alloc_sleep_millisecs));
- remove_wait_queue(&khugepaged_wait, &wait);
- }
+ if (!hpage)
+ khugepaged_alloc_sleep();
} while (unlikely(!hpage) &&
likely(khugepaged_enabled()));
return hpage;
}
+#endif
static void khugepaged_loop(void)
{
struct page *hpage;
+#ifdef CONFIG_NUMA
+ hpage = NULL;
+#endif
while (likely(khugepaged_enabled())) {
+#ifndef CONFIG_NUMA
hpage = khugepaged_alloc_hugepage();
if (unlikely(!hpage))
break;
+#else
+ if (IS_ERR(hpage)) {
+ khugepaged_alloc_sleep();
+ hpage = NULL;
+ }
+#endif
khugepaged_do_scan(&hpage);
+#ifndef CONFIG_NUMA
if (hpage)
put_page(hpage);
+#endif
+ try_to_freeze();
+ if (unlikely(kthread_should_stop()))
+ break;
if (khugepaged_has_work()) {
DEFINE_WAIT(wait);
if (!khugepaged_scan_sleep_millisecs)
khugepaged_scan_sleep_millisecs));
remove_wait_queue(&khugepaged_wait, &wait);
} else if (khugepaged_enabled())
- wait_event_interruptible(khugepaged_wait,
- khugepaged_wait_event());
+ wait_event_freezable(khugepaged_wait,
+ khugepaged_wait_event());
}
}
{
struct mm_slot *mm_slot;
+ set_freezable();
set_user_nice(current, 19);
/* serialize with start_khugepaged() */
mutex_lock(&khugepaged_mutex);
if (!khugepaged_enabled())
break;
+ if (unlikely(kthread_should_stop()))
+ break;
}
spin_lock(&khugepaged_mm_lock);
put_page(page);
BUG_ON(pmd_trans_huge(*pmd));
}
+
+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);
+ }
+}
git.openpandora.org / pandora-kernel.git / blobdiff