[RFC v2 04/10] mm: Handle range lock field when collapsing huge pages

Laurent Dufour
2017-05-24T11:20:54Z

When collapsing huge pages from swap in operatioin, 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.

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
mm/khugepaged.c | 39 +++++++++++++++++++++++++++++++++------
1 file changed, 33 insertions(+), 6 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 945fd1ca49b5..6357f32608a5 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -872,7 +872,11 @@ 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
+#ifdef CONFIG_MEM_RANGE_LOCK
+ , struct range_lock *range
+#endif
+ )
{
int swapped_in = 0, ret = 0;
struct vm_fault vmf = {
@@ -881,6 +885,9 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm,
.flags = FAULT_FLAG_ALLOW_RETRY,
.pmd = pmd,
.pgoff = linear_page_index(vma, address),
+#ifdef CONFIG_MEM_RANGE_LOCK
+ .lockrange = range,
+#endif
};

/* we only decide to swapin, if there is enough young ptes */
@@ -927,7 +934,11 @@ 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)
+ int node, int referenced
+#ifdef CONFIG_MEM_RANGE_LOCK
+ , struct range_lock *range
+#endif
+ )
{
pmd_t *pmd, _pmd;
pte_t *pte;
@@ -985,7 +996,11 @@ 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
+#ifdef CONFIG_MEM_RANGE_LOCK
+ , range
+#endif
+ )) {
mem_cgroup_cancel_charge(new_page, memcg, true);
up_read(&mm->mmap_sem);
goto out_nolock;
@@ -1092,7 +1107,11 @@ 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
+#ifdef CONFIG_MEM_RANGE_LOCK
+ , struct range_lock *range
+#endif
+ )
{
pmd_t *pmd;
pte_t *pte, *_pte;
@@ -1206,7 +1225,11 @@ 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
+#ifdef CONFIG_MEM_RANGE_LOCK
+ , range
+#endif
+ );
}
out:
trace_mm_khugepaged_scan_pmd(mm, page, writable, referenced,
@@ -1727,7 +1750,11 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
} else {
ret = khugepaged_scan_pmd(mm, vma,
khugepaged_scan.address,
- hpage);
+ hpage
+#ifdef CONFIG_MEM_RANGE_LOCK
+ , &range
+#endif
+ );
}
/* move to next address */
khugepaged_scan.address += HPAGE_PMD_SIZE;
--
2.7.4