@@ -813,19 +813,18 @@ static int khugepaged_find_target_node(struct collapse_control *cc)
}
#endif
-static struct page *
-khugepaged_alloc_page(struct page **hpage, gfp_t gfp, int node)
+static bool khugepaged_alloc_page(struct page **hpage, gfp_t gfp, int node)
{
*hpage = __alloc_pages_node(node, gfp, HPAGE_PMD_ORDER);
if (unlikely(!*hpage)) {
count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
*hpage = ERR_PTR(-ENOMEM);
- return NULL;
+ return false;
}
prep_transhuge_page(*hpage);
count_vm_event(THP_COLLAPSE_ALLOC);
- return *hpage;
+ return true;
}
/*
@@ -921,10 +920,24 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm,
return true;
}
-static void collapse_huge_page(struct mm_struct *mm,
- unsigned long address,
- struct page **hpage,
- int node, int referenced, int unmapped)
+static int alloc_charge_hpage(struct page **hpage, struct mm_struct *mm,
+ struct collapse_control *cc)
+{
+ /* Only allocate from the target node */
+ gfp_t gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_THISNODE;
+ int node = khugepaged_find_target_node(cc);
+
+ if (!khugepaged_alloc_page(hpage, gfp, node))
+ return SCAN_ALLOC_HUGE_PAGE_FAIL;
+ if (unlikely(mem_cgroup_charge(page_folio(*hpage), mm, gfp)))
+ return SCAN_CGROUP_CHARGE_FAIL;
+ count_memcg_page_event(*hpage, THP_COLLAPSE_ALLOC);
+ return SCAN_SUCCEED;
+}
+
+static void collapse_huge_page(struct mm_struct *mm, unsigned long address,
+ struct page **hpage, int referenced,
+ int unmapped, struct collapse_control *cc)
{
LIST_HEAD(compound_pagelist);
pmd_t *pmd, _pmd;
@@ -935,13 +948,9 @@ static void collapse_huge_page(struct mm_struct *mm,
int isolated = 0, result = 0;
struct vm_area_struct *vma;
struct mmu_notifier_range range;
- gfp_t gfp;
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
- /* Only allocate from the target node */
- gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_THISNODE;
-
/*
* Before allocating the hugepage, release the mmap_lock read lock.
* The allocation can take potentially a long time if it involves
@@ -949,17 +958,12 @@ static void collapse_huge_page(struct mm_struct *mm,
* that. We will recheck the vma after taking it again in write mode.
*/
mmap_read_unlock(mm);
- new_page = khugepaged_alloc_page(hpage, gfp, node);
- if (!new_page) {
- result = SCAN_ALLOC_HUGE_PAGE_FAIL;
- goto out_nolock;
- }
- if (unlikely(mem_cgroup_charge(page_folio(new_page), mm, gfp))) {
- result = SCAN_CGROUP_CHARGE_FAIL;
+ result = alloc_charge_hpage(hpage, mm, cc);
+ if (result != SCAN_SUCCEED)
goto out_nolock;
- }
- count_memcg_page_event(new_page, THP_COLLAPSE_ALLOC);
+
+ new_page = *hpage;
mmap_read_lock(mm);
result = hugepage_vma_revalidate(mm, address, &vma);
@@ -1233,10 +1237,9 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
out_unmap:
pte_unmap_unlock(pte, ptl);
if (ret) {
- node = khugepaged_find_target_node(cc);
/* collapse_huge_page will return with the mmap_lock released */
- collapse_huge_page(mm, address, hpage, node,
- referenced, unmapped);
+ collapse_huge_page(mm, address, hpage, referenced, unmapped,
+ cc);
}
out:
trace_mm_khugepaged_scan_pmd(mm, page, writable, referenced,
@@ -1504,7 +1507,7 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
* @file: file that collapse on
* @start: collapse start address
* @hpage: new allocated huge page for collapse
- * @node: appointed node the new huge page allocate from
+ * @cc: collapse context and scratchpad
*
* Basic scheme is simple, details are more complex:
* - allocate and lock a new huge page;
@@ -1521,12 +1524,11 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
* + restore gaps in the page cache;
* + unlock and free huge page;
*/
-static void collapse_file(struct mm_struct *mm,
- struct file *file, pgoff_t start,
- struct page **hpage, int node)
+static void collapse_file(struct mm_struct *mm, struct file *file,
+ pgoff_t start, struct page **hpage,
+ struct collapse_control *cc)
{
struct address_space *mapping = file->f_mapping;
- gfp_t gfp;
struct page *new_page;
pgoff_t index, end = start + HPAGE_PMD_NR;
LIST_HEAD(pagelist);
@@ -1538,20 +1540,11 @@ static void collapse_file(struct mm_struct *mm,
VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem);
VM_BUG_ON(start & (HPAGE_PMD_NR - 1));
- /* Only allocate from the target node */
- gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_THISNODE;
-
- new_page = khugepaged_alloc_page(hpage, gfp, node);
- if (!new_page) {
- result = SCAN_ALLOC_HUGE_PAGE_FAIL;
+ result = alloc_charge_hpage(hpage, mm, cc);
+ if (result != SCAN_SUCCEED)
goto out;
- }
- if (unlikely(mem_cgroup_charge(page_folio(new_page), mm, gfp))) {
- result = SCAN_CGROUP_CHARGE_FAIL;
- goto out;
- }
- count_memcg_page_event(new_page, THP_COLLAPSE_ALLOC);
+ new_page = *hpage;
/*
* Ensure we have slots for all the pages in the range. This is
@@ -1963,8 +1956,7 @@ static void khugepaged_scan_file(struct mm_struct *mm, struct file *file,
result = SCAN_EXCEED_NONE_PTE;
count_vm_event(THP_SCAN_EXCEED_NONE_PTE);
} else {
- node = khugepaged_find_target_node(cc);
- collapse_file(mm, file, start, hpage, node);
+ collapse_file(mm, file, start, hpage, cc);
}
}
The following code is duplicated in collapse_huge_page() and collapse_file(): gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_THISNODE; new_page = khugepaged_alloc_page(hpage, gfp, node); if (!new_page) { result = SCAN_ALLOC_HUGE_PAGE_FAIL; goto out; } if (unlikely(mem_cgroup_charge(page_folio(new_page), mm, gfp))) { result = SCAN_CGROUP_CHARGE_FAIL; goto out; } count_memcg_page_event(new_page, THP_COLLAPSE_ALLOC); Also, "node" is passed as an argument to both collapse_huge_page() and collapse_file() and obtained the same way, via khugepaged_find_target_node(). Move all this into a new helper, alloc_charge_hpage(), and remove the duplicate code from collapse_huge_page() and collapse_file(). Also, simplify khugepaged_alloc_page() by returning a bool indicating allocation success instead of a copy of the allocated struct page *. Suggested-by: Peter Xu <peterx@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Signed-off-by: Zach O'Keefe <zokeefe@google.com> --- mm/khugepaged.c | 78 ++++++++++++++++++++++--------------------------- 1 file changed, 35 insertions(+), 43 deletions(-)