Convert result variables and return types from int to enum scan_result throughout khugepaged code. This improves type safety and code clarity by making the intent explicit. No functional change. Signed-off-by: Shivank Garg --- mm/khugepaged.c | 111 +++++++++++++++++++++++++----------------------- 1 file changed, 57 insertions(+), 54 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 04ff0730c9a1..6892b23d6fc4 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -537,17 +537,18 @@ static void release_pte_pages(pte_t *pte, pte_t *_pte, } } -static int __collapse_huge_page_isolate(struct vm_area_struct *vma, - unsigned long start_addr, - pte_t *pte, - struct collapse_control *cc, - struct list_head *compound_pagelist) +static enum scan_result __collapse_huge_page_isolate(struct vm_area_struct *vma, + unsigned long start_addr, + pte_t *pte, + struct collapse_control *cc, + struct list_head *compound_pagelist) { struct page *page = NULL; struct folio *folio = NULL; unsigned long addr = start_addr; pte_t *_pte; - int none_or_zero = 0, shared = 0, result = SCAN_FAIL, referenced = 0; + int none_or_zero = 0, shared = 0, referenced = 0; + enum scan_result result = SCAN_FAIL; for (_pte = pte; _pte < pte + HPAGE_PMD_NR; _pte++, addr += PAGE_SIZE) { @@ -780,13 +781,13 @@ static void __collapse_huge_page_copy_failed(pte_t *pte, * @ptl: lock on raw pages' PTEs * @compound_pagelist: list that stores compound pages */ -static int __collapse_huge_page_copy(pte_t *pte, struct folio *folio, +static enum scan_result __collapse_huge_page_copy(pte_t *pte, struct folio *folio, pmd_t *pmd, pmd_t orig_pmd, struct vm_area_struct *vma, unsigned long address, spinlock_t *ptl, struct list_head *compound_pagelist) { unsigned int i; - int result = SCAN_SUCCEED; + enum scan_result result = SCAN_SUCCEED; /* * Copying pages' contents is subject to memory poison at any iteration. @@ -898,10 +899,9 @@ static int hpage_collapse_find_target_node(struct collapse_control *cc) * Returns enum scan_result value. */ -static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address, - bool expect_anon, - struct vm_area_struct **vmap, - struct collapse_control *cc) +static enum scan_result hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address, + bool expect_anon, struct vm_area_struct **vmap, + struct collapse_control *cc) { struct vm_area_struct *vma; enum tva_type type = cc->is_khugepaged ? TVA_KHUGEPAGED : @@ -930,7 +930,7 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address, return SCAN_SUCCEED; } -static inline int check_pmd_state(pmd_t *pmd) +static inline enum scan_result check_pmd_state(pmd_t *pmd) { pmd_t pmde = pmdp_get_lockless(pmd); @@ -953,9 +953,9 @@ static inline int check_pmd_state(pmd_t *pmd) return SCAN_SUCCEED; } -static int find_pmd_or_thp_or_none(struct mm_struct *mm, - unsigned long address, - pmd_t **pmd) +static enum scan_result find_pmd_or_thp_or_none(struct mm_struct *mm, + unsigned long address, + pmd_t **pmd) { *pmd = mm_find_pmd(mm, address); if (!*pmd) @@ -964,12 +964,12 @@ static int find_pmd_or_thp_or_none(struct mm_struct *mm, return check_pmd_state(*pmd); } -static int check_pmd_still_valid(struct mm_struct *mm, - unsigned long address, - pmd_t *pmd) +static enum scan_result check_pmd_still_valid(struct mm_struct *mm, + unsigned long address, + pmd_t *pmd) { pmd_t *new_pmd; - int result = find_pmd_or_thp_or_none(mm, address, &new_pmd); + enum scan_result result = find_pmd_or_thp_or_none(mm, address, &new_pmd); if (result != SCAN_SUCCEED) return result; @@ -985,15 +985,15 @@ static int check_pmd_still_valid(struct mm_struct *mm, * Called and returns without pte mapped or spinlocks held. * Returns result: if not SCAN_SUCCEED, mmap_lock has been released. */ -static int __collapse_huge_page_swapin(struct mm_struct *mm, - struct vm_area_struct *vma, - unsigned long start_addr, pmd_t *pmd, - int referenced) +static enum scan_result __collapse_huge_page_swapin(struct mm_struct *mm, + struct vm_area_struct *vma, + unsigned long start_addr, pmd_t *pmd, + int referenced) { int swapped_in = 0; vm_fault_t ret = 0; unsigned long addr, end = start_addr + (HPAGE_PMD_NR * PAGE_SIZE); - int result; + enum scan_result result; pte_t *pte = NULL; spinlock_t *ptl; @@ -1062,8 +1062,8 @@ static int __collapse_huge_page_swapin(struct mm_struct *mm, return result; } -static int alloc_charge_folio(struct folio **foliop, struct mm_struct *mm, - struct collapse_control *cc) +static enum scan_result alloc_charge_folio(struct folio **foliop, struct mm_struct *mm, + struct collapse_control *cc) { gfp_t gfp = (cc->is_khugepaged ? alloc_hugepage_khugepaged_gfpmask() : GFP_TRANSHUGE); @@ -1090,9 +1090,9 @@ static int alloc_charge_folio(struct folio **foliop, struct mm_struct *mm, return SCAN_SUCCEED; } -static int collapse_huge_page(struct mm_struct *mm, unsigned long address, - int referenced, int unmapped, - struct collapse_control *cc) +static enum scan_result collapse_huge_page(struct mm_struct *mm, unsigned long address, + int referenced, int unmapped, + struct collapse_control *cc) { LIST_HEAD(compound_pagelist); pmd_t *pmd, _pmd; @@ -1100,7 +1100,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address, pgtable_t pgtable; struct folio *folio; spinlock_t *pmd_ptl, *pte_ptl; - int result = SCAN_FAIL; + enum scan_result result = SCAN_FAIL; struct vm_area_struct *vma; struct mmu_notifier_range range; @@ -1246,15 +1246,15 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address, return result; } -static int hpage_collapse_scan_pmd(struct mm_struct *mm, - struct vm_area_struct *vma, - unsigned long start_addr, bool *mmap_locked, - struct collapse_control *cc) +static enum scan_result hpage_collapse_scan_pmd(struct mm_struct *mm, + struct vm_area_struct *vma, + unsigned long start_addr, bool *mmap_locked, + struct collapse_control *cc) { pmd_t *pmd; pte_t *pte, *_pte; - int result = SCAN_FAIL, referenced = 0; - int none_or_zero = 0, shared = 0; + int none_or_zero = 0, shared = 0, referenced = 0; + enum scan_result result = SCAN_FAIL; struct page *page = NULL; struct folio *folio = NULL; unsigned long addr; @@ -1441,8 +1441,8 @@ static void collect_mm_slot(struct mm_slot *slot) } /* folio must be locked, and mmap_lock must be held */ -static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr, - pmd_t *pmdp, struct folio *folio, struct page *page) +static enum scan_result set_huge_pmd(struct vm_area_struct *vma, unsigned long addr, + pmd_t *pmdp, struct folio *folio, struct page *page) { struct mm_struct *mm = vma->vm_mm; struct vm_fault vmf = { @@ -1477,10 +1477,11 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr, return SCAN_SUCCEED; } -static int try_collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, - bool install_pmd) +static enum scan_result try_collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, + bool install_pmd) { - int nr_mapped_ptes = 0, result = SCAN_FAIL; + enum scan_result result = SCAN_FAIL; + int nr_mapped_ptes = 0; unsigned int nr_batch_ptes; struct mmu_notifier_range range; bool notified = false; @@ -1862,9 +1863,9 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff) * + unlock old pages * + unlock and free huge page; */ -static int collapse_file(struct mm_struct *mm, unsigned long addr, - struct file *file, pgoff_t start, - struct collapse_control *cc) +static enum scan_result collapse_file(struct mm_struct *mm, unsigned long addr, + struct file *file, pgoff_t start, + struct collapse_control *cc) { struct address_space *mapping = file->f_mapping; struct page *dst; @@ -1872,7 +1873,8 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, pgoff_t index = 0, end = start + HPAGE_PMD_NR; LIST_HEAD(pagelist); XA_STATE_ORDER(xas, &mapping->i_pages, start, HPAGE_PMD_ORDER); - int nr_none = 0, result = SCAN_SUCCEED; + enum scan_result result = SCAN_SUCCEED; + int nr_none = 0; bool is_shmem = shmem_file(file); VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem); @@ -2293,16 +2295,16 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, return result; } -static int hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr, - struct file *file, pgoff_t start, - struct collapse_control *cc) +static enum scan_result hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr, + struct file *file, pgoff_t start, + struct collapse_control *cc) { struct folio *folio = NULL; struct address_space *mapping = file->f_mapping; XA_STATE(xas, &mapping->i_pages, start); int present, swap; int node = NUMA_NO_NODE; - int result = SCAN_SUCCEED; + enum scan_result result = SCAN_SUCCEED; present = 0; swap = 0; @@ -2400,7 +2402,7 @@ static int hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr, return result; } -static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result, +static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result *result, struct collapse_control *cc) __releases(&khugepaged_mm_lock) __acquires(&khugepaged_mm_lock) @@ -2561,7 +2563,7 @@ static void khugepaged_do_scan(struct collapse_control *cc) unsigned int progress = 0, pass_through_head = 0; unsigned int pages = READ_ONCE(khugepaged_pages_to_scan); bool wait = true; - int result = SCAN_SUCCEED; + enum scan_result result = SCAN_SUCCEED; lru_add_drain_all(); @@ -2774,7 +2776,8 @@ int madvise_collapse(struct vm_area_struct *vma, unsigned long start, struct collapse_control *cc; struct mm_struct *mm = vma->vm_mm; unsigned long hstart, hend, addr; - int thps = 0, last_fail = SCAN_FAIL; + enum scan_result last_fail = SCAN_FAIL; + int thps = 0; bool mmap_locked = true; BUG_ON(vma->vm_start > start); @@ -2796,7 +2799,7 @@ int madvise_collapse(struct vm_area_struct *vma, unsigned long start, for (addr = hstart; addr < hend; addr += HPAGE_PMD_SIZE) { bool retried = false; - int result = SCAN_FAIL; + enum scan_result result = SCAN_FAIL; if (!mmap_locked) { retry: -- 2.43.0