From: Davidlohr Bueso <dave@xxxxxxxxxxxx>
When collapsing huge pages from swapin, a vm_fault structure is built
and passed to do_swap_page(). The new range field of the vm_fault
structure must be set correctly when dealing with range_lock.
We teach the main workhorse, khugepaged_scan_mm_slot(), to pass on
a full range lock.
Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
---
mm/khugepaged.c | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index b7e2268dfc9a..0b91ce730160 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -873,7 +873,8 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
static bool __collapse_huge_page_swapin(struct mm_struct *mm,
struct vm_area_struct *vma,
unsigned long address, pmd_t *pmd,
- int referenced)
+ int referenced,
+ struct range_lock *mmrange)
{
int swapped_in = 0, ret = 0;
struct vm_fault vmf = {
@@ -882,6 +883,7 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm,
.flags = FAULT_FLAG_ALLOW_RETRY,
.pmd = pmd,
.pgoff = linear_page_index(vma, address),
+ .lockrange = mmrange,
};
/* we only decide to swapin, if there is enough young ptes */
@@ -926,9 +928,10 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm,
}
static void collapse_huge_page(struct mm_struct *mm,
- unsigned long address,
- struct page **hpage,
- int node, int referenced)
+ unsigned long address,
+ struct page **hpage,
+ int node, int referenced,
+ struct range_lock *mmrange)
{
pmd_t *pmd, _pmd;
pte_t *pte;
@@ -986,7 +989,7 @@ static void collapse_huge_page(struct mm_struct *mm,
* If it fails, we release mmap_sem and jump out_nolock.
* Continuing to collapse causes inconsistency.
*/
- if (!__collapse_huge_page_swapin(mm, vma, address, pmd, referenced)) {
+ if (!__collapse_huge_page_swapin(mm, vma, address, pmd, referenced, mmrange)) {
mem_cgroup_cancel_charge(new_page, memcg, true);
up_read(&mm->mmap_sem);
goto out_nolock;
@@ -1093,7 +1096,8 @@ static void collapse_huge_page(struct mm_struct *mm,
static int khugepaged_scan_pmd(struct mm_struct *mm,
struct vm_area_struct *vma,
unsigned long address,
- struct page **hpage)
+ struct page **hpage,
+ struct range_lock *mmrange)
{
pmd_t *pmd;
pte_t *pte, *_pte;
@@ -1207,7 +1211,8 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
if (ret) {
node = khugepaged_find_target_node();
/* collapse_huge_page will return with the mmap_sem released */
- collapse_huge_page(mm, address, hpage, node, referenced);
+ collapse_huge_page(mm, address, hpage, node, referenced,
+ mmrange);
}
out:
trace_mm_khugepaged_scan_pmd(mm, page, writable, referenced,
@@ -1658,6 +1663,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
struct mm_struct *mm;
struct vm_area_struct *vma;
int progress = 0;
+ DEFINE_RANGE_LOCK_FULL(mmrange);
VM_BUG_ON(!pages);
VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
@@ -1731,7 +1737,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
} else {
ret = khugepaged_scan_pmd(mm, vma,
khugepaged_scan.address,
- hpage);
+ hpage, &mmrange);
}
/* move to next address */
khugepaged_scan.address += HPAGE_PMD_SIZE;
--
2.13.6
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